Monday, Aug 3, 2015

Glossary of Avian Medical Terms - Avian Health & Diseases

Krissyby Jeannine Miesle, MA
Allied Member, Association of Avian Veterinarians

Available for Professional Writing, Editing, Proofing

Index of Bird Diseases ... Symptoms and Potential Causes ... Bird Species and Diseases They are Most Susceptible to ... Bird Health Care ... Medications Used in Avian and Exotic Medicine and Pharmaceutical Terms ... How to administer oral medications to a bird

A ... B ... C ... D ... E ... F ... G ... H ... I ... J ... K ... L ... M ... N ... O ... P ... Q ... R ... S ... T ... U ... V ... W ... Y ... Z

Areas of animal:

  • Anterior: toward the front
  • Caudal or posterior: toward the back end, tail or rear; near tail or hind parts, toward the tail region, opposite of cranial
  • Cranial or Anterior: toward north wall or head
  • Distal: located far from the point of attachment, as a bone
  • Distal: situated farthest away from the point of origin or attachment, as a limb or bone, terminal
  • Dorsal: toward ceiling or back
  • Flank: lateral area posterior to the side of the body; extends back the base of the tail
  • Lateral: toward east or west wall or side
  • Medial: toward midline, away from east or west walls
  • Occiput: hindhead: back portion of the bird’s crown; elongated feathers
  • Posteriad/posterior: toward the rear
  • Prolateral: side area by neck; projecting from or on the side facing forward
  • Proventer region: above the vent
  • Proximal: situated closest to or toward the point of origin or attachment, as a limb or bone; nearer to the point of reference or to the center of the body. For example, the elbow is proximal to the hand. See also distal
  • Ventral: toward floor, or belly

Prefixes and Suffixes

Alphabetic Listing of Bird Anatomy, Functions and Diseases:


Abdomen: the ventral part of the bird, homologous to the human stomach region (belly); The area between the vent and the posterior sternum. The flight muscles are located between the belly and the breast and most of the bird’s digestive organs are located in the abdomen

Abdominocentesis: procedure of going into abdominal cavity and drawing out fluid

Acinar: the smallest secreting portion of a gland

Acinar holocrine sebaceous glands: smallest secreting portion of the gland  releases the secretion, sebum. Small glands that release sebum

Acetabulum (a): a socket of hipbone that receives the head of a thighbone

Acinetobacter: one of the gram-negative pathogenic (disease-
causing) bacteria; one of the milder pathogens

Acquired disease: caused by disorder, injury or tumor

Acuminate: abruptly narrow to a sharp point

Acute: sharp or severe, having a rapid onset, severe symptoms, and a short course

Adenocarcinomas: malignant tumor arising from secretory epithelium; malignant tumor of gland-like structure

Adenoma: benign tumor

Adenovirus: causes hepatitis in birds

Adipose: fatty, tissue consisting of fat

Adjuvent: drugs or chemo/radiation therapy; a supplemental treatment; a substance used to illicit a stronger immune response or hasten immune response

Adsorb: to attract and retain other material on the surface

Aerobic bacteria, bacteria that grow in the presence of oxygen Anaerobic bacteria, bacteria that grow in the absence of oxygen

Aeromonas: nasty gram-negative, usually serious, grows in air

Aerophagia: gulping of air, spasmodic swallowing of air, nervousness and anxiety, gas in intestinal tract

Aerosol: a system in which solid or liquid particles are suspended in air or other gas

Aflatoxins: toxic compound composed of certain molds, contaminates, stored food, cause aspergillosis

Airfoil: special shape found in wings of birds that produces a lifting effect as it moves forward through air

Air sacs: thin membrane of the avian respiratory system that allows unidirectional flow of air into the lungs and through the body; total of 9 air sacs: 4 paired (2 cervical sacs, 2 anterior thoracic sacs, 2 posterior thoracic sacs, 2 abdominal sacs) and 1 unpaired (interclavicular); system of thin-walled membranous sacs found only in birds; they fill parts of birds’ body cavities and penetrate their muscles and bones. They interconnect with each other and with a bird’s lungs to form an efficient one-way path for air movement during breathing, and they also help in removal of waste heat generated during flight. They are not used for exchanging oxygen and carbon dioxide.

Air sac mite: small dark mites in windpipe and air sacs; their  irritation leading to asphyxiation, wheezing, whistling to breath. Treatment: Ivomectin/Ivermectin medication

Air space: pocket of air between the shell membranes at the large end of a bird egg; as the developing embryo uses water and additional water evaporates from the shell, air moves into the egg from outside, expanding the air space

Agen’esis: absence of a body part

Albumen: egg white; albumen is composed primarily of water and protein

Albinism: An abnormal lack of pigment (such as Albinos)

Aliquots: sample

Allantois: a membranous sac that balloons off a bird embryo’s gut; solid wastes produced by the developing embryo that can’t be passed through the eggshell are diverted into the allantois

Allo-feeding/preening: mutual feeding/preening behavior

Altricial young: young birds that hatch underdeveloped, naked or with sparse down; helpless young requiring complete parental care’
- Precocial: birds that hatch in a relatively developed state; with down feathers and eyes open;  able to walk, swim or eat on their own

Alula: small joint on the bird’s wing, similar to the human thumb, with three or four quill-like feathers attached. It is a necessity for low speed flight and maneuverability. The feathers function much like the slats on airplanes by increasing the camber of the wing, helping the bird to land and take off; small wing-like group of feathers at the bend of the wing, supported by the anterior-most digit.

Alular quills: the three feathers attached to the alula originating from the base of the primaries (longest wing feathers). They are essential for low-speed flight and aid in coordinated landing and take-off

Alular quill coverts: smaller feathers covering the quill of each flight feather; each wing has primary, secondary and tertiary coverts, based on the location of the feather.

Alveoli: small cavity, cell or pit on the surface of an organ

Ambient: surrounding, as in the nearby or “ambient” air temperature

Amino Acid: any one of a large group of compounds containing the amino and carboxyl group. They occur naturally in plant and animal tissue and are the building blocks of various proteins

Amylase: produced in saliva, enzyme which begins to break down the starches in digestion

Anaerobe: an organism that grows without air; some are very nasty; e.g., the clostridium that causes gangrene is an anaerobe; many are harmless, however

Analgesic: drug that relieves pain, having the properties of pain relief

Anamnesis: history of bird and current problems, all about caretaking and environment, husbandry, changes

Anechoic: produced or characterized by few or no echoes

Anemia: a decrease in the number of circulating red blood cells, a decrease below normal in the amount of hemoglobin in each red blood cell, or a combination of both conditions; causes weakness and debilitation; caused by blood loss, decreased red blood cell production, increased red blood cell destruction; cause of blood trauma, also GI bleeding, hemorrhage, ulcers, liver disease, GI foreign bodies

Angulated: with an angle

Anisodactile: three toes in front and one behind, as in perching wild birds

Anorexia: loss of appetite

Anthelmintic: substance capable of destroying parasitic worms  (intestinal helminths)

Anthropomorphism: interpreting behavior of animals in terms of human feelings, motivations or characteristics.

Antibiotic: chemical substance, either natural or synthetic, that kills microorganisms (biocidal activity) or inhibits their growth (biostatic activity) antibiotic, one of a group of medications that are used to treat bacterial infections. Some are called broad-spectrum and are used to treat a wide variety of bacteria. Other are used to treat a specific group of bacteria (Gram positive, Gram negative, aerobic, anaerobic). Some antibiotics kill the offending bacteria (bacteriocidal), others just prevent the bacteria from reproducing (bacteriostatic).Broad-spectrum antibiotic: an antibiotic effective against a large array of microorganisms

Antibody: A specialized protein contained in the blood serum and formed by a certain type of white blood cell (the b-lymphocyte) in response to an antigen to which the animal has been exposed. The antibody destroys or inactivates certain foreign substances that have gained access to the body, especially microbes and their products.

Antigen: bacteria, toxin, foreign cell or other substance that, when introduced into the body, stimulates the production of an antibody. Antigens may be substances such as foreign protein, toxins, bacteria or tissue cells.

Apterium/Apteria: bare, unfeathered areas between the feather tracts (Pterylae); featherless tracts; most useful is apteric tract that exposes the jugular vein for venipuncture

Arthrocentesis: puncture into a joint to remove fluid

Articular/articulated: joint involvement, having a joint, an artificial appendage, limb, joints composed of segments

Ascarids: intestinal parasite—roundworms

Ascites: accumulation of fluid in the peritoneal cavity

Aspergillosis: fungal infection caused by the mold, Aspergillus, usually in respiratory system

Aspirate: to withdraw fluid from a body cavity by use of an aspirator or suction syringe (negative pressures), as in the withdrawal of a blood sample with a syringe and needle; to inhale a fluid or foreign body into the bronchi and lungs, often after vomiting; to draw or remove by suction

Assay: qualitative or quantitative analysis of a substance, esp. drug

Asymptomatic: without symptoms but carrying and/or shedding the disease organisms; young birds will die if infected but most adult birds can contract the virus and remain asymptomatic, amplifying the virus and spreading it to other birds; e.g. polyoma virus

Asynchronous hatching: single clutch hatches over a period of several days; incubation begins when first egg is laid; embryos of earliest laid eggs have already started to develop by the time the later eggs are laid, and they hatch sooner—Synchronous hatching all hatch about the same time

Ataxia: loss of coordination in the muscles, esp. the extremities; resulting in staggering gate

Atonic: lack of muscle tone

Atoxoplasma: liver enlarged, dark area under skin of abdomen, bloody diarrhea, weight loss, dehydrated, depression, sudden death, “Black spot”

Atresea (choanal): the congenital absence, or the pathological closure of an opening, passage or cavity (altresic)

Atrophic Rhinitis: inflammation of nose and mucous membrane resulting in degeneration of tissue from nerve damage

Auditory meatus: ear opening

Auricular feathers:  soft, loose-webbed feathers on the side of the bird’s head that protect the ear. These feathers overlap the ear and as such are also called “ear coverts” or “ear patch.” They can sometimes be a different color depending on the bird species. Birds do not have ear lobes or external pinna like humans and other mammals; however, they do have a slight thickening of the skin around the ear

Auscultation: listening either directly or through a stethoscope or other instrument, to sounds within the body as a method of diagnosis

Autoch’thonus: found in the locality in which it originates, as in a cancer or disease, found in original place, indigenous.

Autochthonus flora: normal flora, takes 3-4 weeks to develop in a chick

Auto’genous: self-produced or self-generated; refers to substances generated in the body

Autogenous vaccine: a suspension made from the material obtained from the lesions of the animal to be vaccinated and used for the prevention, amelioration (to make better), or treatment of a specific infections disease

Autoimmune disease: occurs when body becomes intolerant of its own cells

Avascular: lacking blood vessels in body tissue

Avian influenza, virus, Type A in poultry and humans

Axilla/axillary: region under the wing/between the body and the wing. Similar to the armpit “wingpit;” comprised of the underside base of the wing, extending to the ventral wing lining. Muscles in the area are heavily involved in flight.

Axillary feather: feathers in the Axillary area


Back: dorsal part of the bird between the base of the wings and from the neck to the tail

Bacteria: one-celled micro-organisms that may cause disease

Bactere’mia: presence of bacteria in blood

Bacteriocidal: kills bacteria

Bacteriostatic, halts the growth of bacteria without killing them

Barb: parallel feather rays branching out from each side of the rachis

Barbicel: hooked projection extending from and interlocking the barbules of a feather

Barbules: hooked branches extending from each side of the feather barb; fasten adjacent barbs together

Basophil: a white cell associated with debris cleanup

- maxilla (upper mandible) is movable in parrots, not in mammals
- made possible by the elastic zones in the bones of the face; parrots have rasplike ridges that run transversely inside the maxilla for cracking nuts; rictal area is along the sides of the upper and lower mandibles; beak resembles skin microscopically because it contains dermis and epidermis, but epidermis is very thick and contains calcium and keratin, which gives it its hardness;
- beak has bill-tip organ—sensitive and used for feeling environment, allows bird to discriminate between food and other particles
- nerve endings for the beak are in channels that can be seen as white dots in a black beak, never cut them

Bile: yellowish-green fluid produced in the liver, stored in the glallbladder, and passed through ducts to the small intestine, where it plays an essential role in emulsifying fats
Bile acids: the only specific test for liver disease in birds

Biliary duct: relating to bile or the transporting of bile; affecting a bile duct or the system of ducts in the liver

Biliverdinuria: dark green bile in urine indicative of liver disease; increased excretions of biliverdin (bile pigment in blood) most often indicates hepatitis. Vsudrz; obesity and high-fat diet.

Biopsy: removal of small piece of tissue for microscopic exam

Bipedal: standing on 2 legs

Blood feather: new feather has venous and arterial blood supply; thick, purple appearance, as feather matures, blood supply recedes

Body: torso, main mass not including appendages, such as wings, tail and legs. Contains all essential organs and a large part of the bird’s muscle mass

Bolus: soft, round mass of chewed food, lump; round mass of medicinal material, larger than a pill

Booted: not divided into scales (tarsus); of the tarsus of certain birds, covered with a continuous, horny, boot-like sheath.

Bronchitis: inflammation of bronchial passages

Bronchography:describing the bronchi

Brood: combined nestlings in a nest; sitting on hatched young, sheltering to keep warm and for protection

Brood patch:  area over breast that becomes thickened, vascular and loses feathers during brooding period; transfers heat from hen to eggs

Brood reduction: feeding most vigorously- begging offspring then moving on to another; strongest survive in years of low food supply, in good years all survive

Bucky technique: to set up an instrument in line with 2 marks (radiography)

Bumblefoot (pododermatitis) lesions on the bottom of the bird’s foot

Bursal: Bursa: sac-like bodily cavity, especially  one located between moving parts, e.g. elbows, shoulder or knee


Cachec’tic (cachec’tin) protein that is released by activated macrophages as an immune system defense and, when the defense is overwhelmed, is the cause of cachexis or toxic shock

Cachect’ic/cachex’ia: general ill health with emaciation, usually occurring in association with cancer or a chronic infection or disease; extreme weight loss

Candidiasis: yeast/fungus infection

Candling: view the content of the egg, determines whether fertility

Cannula: a metal tube for insertion into the body to draw off fluid or to introduce medication, tubular shaped; contains a trocar (sharp, pointed instrument; see definition)

Cap: area on top of the head; color of the cap helps differentiate between similar-looking but different species

Capillaria: internal parasitic worm

Cardiac failure: weakness, anorexia, tachympnea, dyspnea, coughing, abdominal distension due to hepatomegaly and ascites; diagnosis determined by arrhythmia or murmur, x-ray; treatment: flurosemide dose, subcutaneous fluids, oxygen, ultrasound

Cardiomegaly:  abnormal enlargement of the heart

Cardiomyopathy: disease of heart muscle, leads to decreased function with no known cause

Carrier: individual that harbors disease organism;  shows no clinical evidence of that disease but can transmit it to others
- Non-Shedding carrier: individual that harbors disease organism but at time of testing does not show visual evidence of disease and is not contagious; aka latent infection

Caseous:  having the appearance of cheese, one of the forms of tissue death (necrosis)

Casts: things that are shed, e.g., skin, feathers; can cause renal disease

Catecholamines: any one of the chemical neurotransmitters, such as epinephrine and dopamine that have similar effects on the sympathetic nervous system; release of them caused by stress, leads to hyperglycemia, high blood glucose levels

Catobolizin: breaking down of muscle or other tissue; usually due to malnutrition or semi-starvation

CBC: Complete blood count; microscopic examination of the blood that includes counts of red and white blood cells, and a report of the relative numbers of specific types of white blood cells.

Cecum/ceca: (pronounced: see’cum) a diverticulum on each side of the gut at junction of small and large intestines, for additional digestion—found only in ratites and gallinaceous  (larger) birds; blind sac that opens into the colon

Cell mitosis –cell division

Cellulitis: a diffuse inflammation of solid tissue; signs include redness, swelling, pain, loss of function in the affected area

Cere: fleshy area enclosing nostrils; operculum; smooth and featherless patch of skin located where the beak attaches to the forehead; often enlarged and brightly colored such as in parrots and birds of prey

Cervicocephal’ic: area of bones of the neck close to the head (anterior)

Cestode: tapeworm

Chala’za: the gelatinous, milky white, stringy coils of albumen (egg white) that surround and protect the egg yolk and are visible at either end of the yolk as twisted cords. The chalazae attach to the far ends of the eggshell and form a suspension system for the yolk that allows it to rotate throughout embryonic development; twisted chords of albumen connected to the yolk; these cords stabilize the yolk within the egg and keep it from floating against the upper shell surface. This structure also serves to keep the germinal disk in the upward position so it remains next to the heat produced by the incubating parent above

Cheek: between lore, eye, auricula and mandible

Chelation: binding of a substance to a metal

Chest: frontal area on body containing the breastplate (keel) and major flight muscles

Chin: below the beak; does not protrude like a human’s chin, less prominent

Chlamydia/chlamydophilia psittaci: organism responsible for Psittacosis

Chlamydiosis: same as psittacosis, parrot fever or ornithosis, name of choice

Choana (choanae): a slit in the hard palate of a bird’s mouth, connecting the nasal passages with the oral cavity; opening between the nasal cavity and oropharynx (mouth)

Choanal slit; numerous projections or papillae are found at the edge of the choana; connects through passages to the nostrils; glottis fits snugly into the choanal slit when the bird closes its mouth so the bird will have a closed connection from the nostrils to the windpipe.

Choanal papillae: several tiny projections that line the choanal slit; should be sharp; blunting or absence is often attributed to nutritional deficiencies (Hypovitaminosis A) or respiratory illness

Chorioallantoic membrane (CAM): a membrane that forms during embryonic development that eventually lines the inner egg shell surface; it has many capillaries through which oxygen and carbon dioxide gases are exchanged between the embryo and outside air.

Chronic: illness of long duration, slow progression of symptoms

Circovirus: causes PBFD

Clinical: refers to medical matters; e.g.., clinical history, clinical signs; also means bird is presenting symptoms

Clinical diagnosis: assumption of cause of disease based on physical and visual signs

Cloaca: common tube-like chamber or structure through which feces, urine, urates, fluids and eggs pass (above anus or vent)
- Everted cloaca: turned outward or inside out

Cloacal kiss/contact: copulation between birds; frequent copulation: male bird makes sure he is the father of at least some of the young in his nest

Cloacapexy: incision is made in the abdomen, suturing the cloaca to the caudal border of the sternum (abdominal wall) after a prolapse

Cloaca bursa (Bursa of Fabricus): lymphoid gland of the cloaca, believed to function in disease resistance, and closing or disappearing as the bird ages

Clutch: complete set of eggs; those laid in uninterrupted series for a single nesting by one female Clutch size: number of eggs in a clutch

Coagulopathies: a condition affecting the blood’s ability to form a clot; defect in body’s mechanism for blood clotting

Coaptation: joining or adjustment of parts to one another, as broken bone

Co’ccus: spherical microorganism, especially a bacterium (cocci pl)

Coccidia: one celled protozoa that affects digestive tract, causes diarrhea Coccidiosis: protozoan parasite, lives in intestines, lays “eggs” (oocysts)

Coccidiostat: drug that inhibits growth of coccidia

Coliforms: pertaining to coliform bacillus; various species of bacteria inhabiting colon

Collagen: fibrous, insoluble protein that forms part of the supportive framework of the skin, bone, ligaments, cartilage and tendons. Also found in the vitreous humor of the eye as a stiffening agent. Protein abundant in higher animal, esp. skin, bone, cartilage, tendons and teeth

Collar: upper part of neck, located at back of the crown, also called hindneck and nape

Collimate/Collimation/collimated beam: to adjust accurately the line of sight (radiography)

Commensal: living on or within another organism and deriving benefit from that organism without harming it.

Comminuted fracture: bone fracture in which the separated parts are splintered or fragmented, divided into small parts, powdered or pulverized

Commissure: (gape) line formed by meeting of maxilla and mandible; hinge where the mandibles meet; most birds can only move lower jaw, but parrots can move both

Communal roost: group of birds gathering to spend the night together, sleeping; the place they roost

Compensation: making up for or counterbalancing any defect of function or structure
Decompensation: failure of the body to make up for defects of function or structure

Compressed: flattened from side to side

Concha (conchae): turbinate bone in the nose, Spongy bones of the nasal passages; along with sinuses, in head, hollow spaces but with infection may become clogged with liquid, mucous, abscess material or debris

Concretion: solid, hard mass

Congeners: something of same type: somebody or something that belongs to the same class, group, or type; for example, an animal or plant of the same genus as another animal or plant, or two elements belonging to the same group

Conjunctivitis: watery eye discharge, swollen and red conjunctiva, swollen eyelids, partial eye paralysis, weak jaw tone, mostly in lutinos, inherited, no infection

Contact call: sound produced by a bird that informs nearby birds of the caller’s location; often uttered by mate

Copraphagia: eating feces

Coracoid bone: extra bone in shoulder, acts as strut to counteract the pressure of downbeat of wings

Cornified: having a keratinous or horny covering

Corticosteroids: natural steroid: a steroid hormone produced by the adrenal gland and involved in metabolism and immune response; any of the hormones produced by the cortex (outer layer) of the adrenal glands; these substances may also be produced synthetically. Their action is to allow many biochemical reactions to proceed at optimum rates.

Courtship displays: performed for opposite sex to attract a mate, maintain a pair bond, or stimulate breeding behavior

Coverts: smaller feathers covering large wing and tail feathers; partly covering the flight feathers on wings and tail; help streamline the bird’s profile, reducing frictional drag as it flies

Crest: the tuft of feathers on the head of the bird; larger in males than in females; increase visibility to predators, but also to potential mate; the more elaborate the crest, the healthier the bird is, females evaluate a potential mate by his crest

Crissum: feathers in a triangular area on the undersurface of a bird between the vent and the base of the tail feathers; can tell whether a bird is adult or juvenile by crissum; adult females have dusky edge to most of the feathers of the crissum, juvenile females have nearly pure white crissum

Crop (ingluvies): located between cervical esophagus and thoracic esophagus; an outpouching of the esophagus and not an organ by itself; oriented transversely across the neck;

Crop ilius: crop obstruction

Crown: top part of the head; sometimes same color as the rest of the bird; holds the crest

Culmen: uppermost central ridge of maxilla; no specific function; males have larger culmen than females

Culture: propagation of microorganisms or living tissue cells in special media conducive to their growth

Cyanosis: bluish, grayish, slate-like or dark purple discoloration of skin and/or mucous membranes. It is caused by a deficiency of oxygen and an excess of carbon dioxide in the blood, as in heart problems, obstruction of the airways, or overdoses of certain drugs.

Cyst: abnormal mass under skin surface

Cystadenomas: benign neoplasm that exhibits glandular differentiation

Cytology: study of microscopic appearance of cells, esp. to diagnose abnormalities and malignancies.

Cytoplasm: thick, viscous substance that surrounds the nucleus of a cell; it constitutes the physical basis of all living activities in the body.

Cytosis: act of destroying particles


Deaminate: to remove the amino group from a compound

Debillitation: Weakening of body

Debridement: removal of foreign matter and dead tissue from a wound

Decompensation: inability of a diseased organ to compensate for its defect; failure of the body to make up for defects of function or structure

Decurved: curved downward toward tip

- Argonine deficiency: results in curled wing feathers
- Riboflavin deficiency: clubbed down feathers
- Pantothenic Acid: niacin and selenium : poor feathering

Definitive Diagnosis: scientific identification of cause of disease

Dehydration: caused by insufficient fluid intake or loss of body fluids

Depopulation: euthanization of bird colony to prevent spread of disease

Depressed: flattened from top to bottom

Dermis: the dense inner layer of skin beneath the epidermis; composed of connective tissue, blood and lymph vessels, feather follicles, and an elaborate sensory nerve network

Dermatitis: inflammation of the skin

Desertion: abandoning the nest

Desiccation: drying out

Desquama’tion: to remove, scale or peel off  in small pieces, especially skin, can be naturally occurring.

Diabetes insipidus: disease in which excessive water is excreted in the urine due to failure of the renal tubes to reabsorb water

Dia’physis/diaphy’sial: the shaft of a long bone, to grow between

Diarrhea: Abnormally fluid-laden fecal discharge; rapid movement of fecal matter through the intestine, resulting in poor absorption of water, nutritive elements, electrolytes; producing frequent, loose bowel movements

Dihedral: wings are said to be dihedral when in the V shape in flight and gliding

Dimorphism/dimorphic: physical characteristics differentiating male from female species; male and female can be identified by distinct difference in plumage or coloration

Diphtheritic: lesions in membranes; false membranes formed in air passages, especially throat

Discrete: consisting of separate, unconnected parts

Down feathers: soft, fluffy feathers whose barbs do not cling together, so they trap more air and provide extra insulation; young birds have natal down before molting into their juvenile plumage

Distal umbilicus: area at the base of the feather vane

Dysfunction: abnormal, inadequate or impaired function of an organ

Dyspharynx: Proventricular worm/parasite

Dysphasia: difficulty swallowing

Dysplasia: abnormal growth of cells, tissues or organs

Dyspneal:  (dyspnea) difficult or labored breathing

Dystrophic: faulty or inadequate nutrition for development; weakening degeneration or abnormal development of muscle; degenerative condition in which muscles atrophy and degenerate


Ears: rounded areas on the bird’s cheek, also called facial discs; auricular meatus

Echogenic: capable of generating or reflecting soundwaves

E-Coli: common gram-negative pathogen in birds; enteric bacteria which is normal in mammals and some birds, but if it is the predominant intestinal bacteria in arboreal birds, or some strains of bacteria which produce toxins, it can cause disease

Ectoparasites: flies, ticks, fleas, lice and mites; anything inhabiting the exterior of a host’s body
Endoparasites: invertebrate or protozoan parasites that inhabit the interior of a host’s body or the skin’s surface

Enteritis: inflammation of the intestine

Ectropion:  Abnormal distortion of the eyelid so that the lower lid turns out, causing a pocket in which tears collect and run out

Edema/edematous: excessive accumulation of serous fluids in an organ tissues/hyperemic
Edematous: Effusing of serous fluid into tissues or body cavity

Efficacious: ability to be effective

Effusion: lymph or blood present in body cavities or tissues as a result of inflammation

Egg: ovum both before and after fertilization; hard-shelled structure laid by bird, containing embryo, yolk and albumin

Egg callosity: egg tooth

Egg laying (chronic) and egg binding: signs: erect posture, straining to pass egg, swollen abdomen, feel egg near vent, soft-shelled hard to feel; most common in hens with no mate, depletes calcium and drains energy; don’t remove eggs, hard boil and replace, breaks cycle; reduce light hours. Causes: obesity, diet low in calcium, chilling, lack of exercise, infection in oviduct.

Egg binding:
- Put bird in warm, humid environment, give calcium supplement every 1-2 hours till egg passes, take to vet for removal, fluid therapy and meds to prevent infection.
- Sometimes egg not in oviduct but laid internally, looks egg-bound but unable to feel egg near vent. Abdomen greatly swollen and full of fluid. Yolk laid internally, prone to develop infection and peritonitis; life-threatening, see vet, leads to Yolk stroke: convulsions, paralysis, sitting on floor not moving, head twisted to side with backward tilt, follows yolk laid internally, fat from yolk absorbed from abdominal cavity into blood vessels; clot of fat is washed away and blocks blood vessel supplying brain; appears to have suffered a stroke.
- Yolk peritonitis: lethargy, abdominal swelling, laid eggs recently or due to lay, tail bobbing; yolk misses oviduct, spills into abdominal cavity, lethal, sudden death. Vet removes fluid from abdominal cavity with syringe; fluid golden (is yolk), blood tests to assess damage, ‘tiels often get diabetes, damaged pancreas, usually temporary; treatment: fluid therapy, warmth, humidity, antibiotics, anti-inflamatories, sometimes surgery needed to flush out abdominal cavity; if chronic, removal of oviduct

Egg tooth: short, pointed, calcareous (containing or characteristic of calcium carbonate) structure on the tip of the maxilla that develops shortly before hatching; used to break out of shell; sloughs off or is reabsorbed within a few days after hatching

Electrocardiography: graphic recording of the electrical activity of the heart, allowing the action of the heart muscle to be studied

Electrolyte: a substance that, in solution, conducts electric current and is decomposed by the passage of an electric current; Positively charged ions in body fluids: Sodium, Potassium, Calcium, and magnesium; Negatively charged: chloride, bicarbonate, phosphate

Elevated: above front toes  

Elisa-A: fluorescent antibody test that detects Psittacosis shedding; positive birds shed the organism only about 12% of the time, so negative does not rule out Psittacosis

Emaciation: loss of flesh through disease or starvation

Emarginate: notched tail feather

Embryo: developing bird still inside egg; Embryonic development: biochemical processes, programmed by DNA that take place within the egg through which a fertilized egg develops the specialized tissues and organs of the embryonic bird

Endemic: particular to or found in a specific area or species

Endocarditis: inflammation of endocardium: serous membrane that lines the cavities of the heart

Endocrine gland: ductless gland that produces an internal secretion that is discharged directly into the blood or lymph and circulated to all parts of the body

Endoscope: long, flexible instrument which can be passed through the body to view organs, uses fiber-optics; endoscopy: surgical procedure allowing vet to see inside body using fiber optic instrument, long, flexible tube with lighted mirror; lens system attached (cannula)

Endoparasite: parasites that live within internal parts of body

Endotoxin: bacterial toxin confined within the body of a bacterium and freed only when the bacterium disintegrates

Enteral: pertaining to the intestines

Enteral nutritional formulas: for birds or humans, have high caloric, protein, fat and carb content, high osmolality, vary from needing some digestion to needing little or none (monomeric) (elemental)

Enteral feeding: a method of feeding in which a tube is forced through the skin into the intestine, allowing nutritious liquid to be forced into the intestine.

Enteric bacteria: normal or pathogenic flora in the intestines

Enteritis: inflammation of the intestines, esp. small intestine

Enterobacter: gram-negative pathogen, one of the milder

Enzootic: diseases prevailing among or afflicting animals in a particular area

Enzymes: special proteins produced by cells which cause chemical changes in other cells, but are not themselves changed

Eosinophil: white cell elevated with parasites and allergies and tissue inflammation in cockatiels

Eosinophilic: (ee-o-sin-o-philic): a granular white blood cell that stains with the dye eosin and is thought to play a part in allergic reactions and the body's response to parasitic diseases

Epicardial: tissue around the heart

Epidemiology: study of the relationship of various factors determining the frequency and distribution of diseases in a community of organisms (people, animals, or plants)

Epiphora: excess tears of the lachrymal glands due to obstruction of lachrymal gland

Epistasis: the stoppage of a secretion or discharge

Epithelium/ Epithelial: A membranous tissue composed of one or more layers of cells that cover most internal and external surfaces of the body and its organs
Epithelial surfaces: skin, mucosal linings of intestinal, reproductive, respiratory and urinary tracts

Epizootic: diseases that spread quickly among animals

Ergot poisoning: disease in cereal grains caused by fungus

Erythrocyte (avian): red blood cell

Esophagus: connects to the crop and then travels through the bones at top of the keel then connects to proventriculus
Etiology: origin or cause of a disease

Euthanasia: act of causing death humanely and painlessly to end suffering; should only be performed by consulting veterinarian

Excrete: to separate and eliminate from an organic body, expel from blood or tissues, waste matter

Excretory urography: function of excreting, radiographic imaging of urinary tract; photograph of all or part of the urinary tract, diagnoses urinary disorders

Exsanguination: pulling/sucking blood to drain the blood, bleed to death, deprive of blood, anemic, bloodless

Extracellular: situated or occurring outside of a cell or group of cells

Extraluminal/intraluminal:  lighting from without, from within; Intraluminal fluid: lights up masses

Extrapair paternity: young in the nest are fathered by a bird other than the resident male

Exocrine: secreting through a duct, e.g., exocrine gland

Exocrine pancreatic insufficiency: not enough fluid being secreted through pancreatic duct

Exophthalmus: protrusion or bulging of the eye due to papilloma; protrusion of eyeball from orbit caused by disease, esp. hyperthyroidism or injury

Exotoxin: toxin produced by a microorganism and excreted into its surrounding medium

Extracellular: situated or occurring outside the cell or group of cells

Extracranial: originating outside of the skull

Extrahepatic: outside the liver

Extrinsic: existing outside the anatomical limits of a part, e.g. Certain muscles or nerves; extrinsic mass: a mass existing on or outside of a part

Exudate/exude: discharge; pour forth or give off, matter coming out e.g. nose; accumulation of fluid, protein, and cellular debris in a cavity; matter that penetrates through vessel walls into adjoining tissue, or the production of pus or serum, coming out gradually in drops, ooze out through small openings, pores, like sweat

Exuviate: cast off, molt

Eye: larger compared to skull, larger than human eyes proportionally; since the skull is lighter compared to the human skull (adjusted for size), the eyes take up about 15% of the weight

Eye deformity (congenital), incomplete separation of eyelids, narrow eyelids, mostly in lutinos, surgery not usually successful

Eye Line: the line of feathers just in front and behind the eyes; extends back from the posterior angle of the eye

Eye ring: pale ring of feathers encircling the eye; narrow, not clear from a distance; not all birds have them

Eyebrow: the arch of feathers growing overtop the bony arch of each eye, similar to the human eye brow; supercilium or superciliary line

Eyelid: birds have one upper and one lower eyelid; lower is more moveable; birds also have a nictitating membrane between both eyelids and the cornea; it has its own lubricating duct equivalent to the human tear duct to clean and protect the eye; in total birds have three eyelids.


False negative/false positive: diagnostic test reads negative/positive, but the animal actually has/doesn’t have the condition

Feather: keratinous structure covering body; central shaft is rachis; barbs and barbules emerge to form the feather, lightweight and strong, for protective covering and mechanism for flight; down feathers insulate and protect skin from moisture

Feather cysts: swellings on body wall, wings or tail; cause: feather grows in underneath skin instead of coming out of feather follicle as normal; inherited or injury to feather follicle, malnutrition, parasites, viral or bacterial infections; treatment: surgery to remove feather follicle, most often seen in macaws and canaries

Feather sheath: thin, cylindrical tube of keratin surrounding and protecting a developing feather; eventually breaks open to let the mature feather unfurl

Feather tracts: (pterylae) areas of a bird’s skin where feathers are attached

Fecal smear: determines parasites, bacteria, fungi, protozoa; feces smeared on slide

Fecal Floatation: fecal test that floats parasite or worm eggs so they can be seen under a microscope; feces are mixed with a chemical solution, spun in a centrifuge, and the fluid lying above the feces at the bottom of the test tube is drawn off, stained and examined under the microscope

Feces: solid body waste discharged from intestines

Feet: located at the terminal part of the legs; most birds have four toes; first toe points backwards (hallux) while the other three point forward; 2nd, 3rd and 4th digits or toes are counted from the inside of the foot out and 2,3, and 4 phalanges, respectively.

Fibroblast: an immature fiber-producing cell that is capable of differentiating into a cell that can produce collagen, bone or cartilage

Filamentous: very long and slender; microbiology: a long strand of similar cells joined end to end, as found in some bacteria and algae

Filoplumes: hair-like feathers

Fine-needle aspirate: suction has been applied to a hollow needle which is inserted into the tissue and a core of the tissue is withdrawn to examine microscopically or culture

Fistula: a narrow passage or duct formed by disease or injury, as one leading from an abscess to a free surface, or from one cavity to another; an opening made into a hollow organ, e.g., eyeball or bladder, for draining; any of various suppurative inflammations. Suppurative/suppurate: to produce or discharge pus, as a wound; the matter produced by suppuration: pus; a medicine or application that promotes the production or discharge of pus

Flagella: whiplike appendages on certain bacteria and protozoa

Flange (oral flange): brightly colored enlargements around the base of the beak in nestling of many species in which the parents feed the young; extend from the corner of the mouth and taper toward the tip of the beak and are supplied with tactile nerve endings; touching the flange causes the mouth to spring open and the colors help parents to place the food properly
Fledgling: baby bird out of nest but unable to fly or feed itself without parents fledging: process of leaving the nest; premature fledging: baby leaves nest before it is developmentally ready; usually dies

Fluoroscope/fluoroscopy: an instrument with which x-ray images of the body can be viewed directly on a screen; used to monitor motility of GI tract

Flight feathers: located on the wing, collectively called remiges (remix) and on the tail, called rectrices;  the flight feathers attach to the bones of the wing; long stiff feathers are subdivided into two groups, primaries (longest wing feathers) and secondaries (shorter, upper "arm" feathers); most involved in propelling and steering birds as they fly

Floaters: birds that do not hold territories or form pair bonds but cruise around areas containing territorial individuals, waiting to take over a territory or nest, or sneak a copulation with a paired bird.

Flocculating agent: substance/chemical capable of penetrating another substance resulting in one being suspended in other

Flora (intestinal): bacteria normally found within the intestine

Fluoroquinolones: anti-microbial drugs that inhibit bacterial gyrase; the enzyme able for coiling DNA’; may induce GI symptoms and siezures

Fomite: an inanimate object than can transmit infectious agents from one person to another; be source of infection; pathogen-contaminated object that can transfer the pathogen to the host

Forehead: area above the eyes and cere

Foreneck: throat, located in the front of the neck, jugulum or throat patch

Free radicals: natural by-products of oxygen metabolism that may contribute to the development of chronic diseases, such as cancer and heart disease

Friable: readily crumbled, brittle, easily reduced to tiny particles, fragile

Fungus/fungi: infect body, skin, and feather follicles; treated with oral antifungal; candida albicans, often found in chicks

Fungicide: substance or chemical that kills fungus


Gallinaceous birds: pheasants, chickens, turkeys, waterfowl

Gamete: one of two cells, sperm or ovum, whose union is necessary in sexual reproduction to initiate the development of a new individual

Gametocyte: cell that produces gametes

Genotypes: a group of organisms having the same genetic construction

Gapeworm: roundworm that lodges in respiratory passages of birds; very rare in pet birds; most often seen in exotic galliforms

Gaping: begging behavior of young birds that begins shortly after hatching in which they open the mouth widely; may be accompanied by a begging call

Gastric lavage: to flush out the crop

Gastroenteritis: inflammation of the lining of the stomach and intestinal track, symptoms are vomiting and diarrhea

Genus: level of classification of organisms above “species” and below “family”

Goit’ogens-goiter producing substances

Germinal spot: light-colored site on the egg yolk where the embryo will eventually develop

Germinative layers: earliest stages of development, deepest layers

Giardia: disease caused by parasitic flagellated protozoa which lodge in intestines; drop cysts (oocytes) which are eaten by other birds ( copraphagia), exists in filth, causes diarrhea, weight loss, malabsorption deficiency disease and feather picking in cockatiels;

Giardia symptoms: cow pie feces, screaming, self mutilation, feather picking, passing whole seeds, undigested foods

Globoid: global or round shape, having globules

Glottis: opening to the windpipe at upper part of trachea, closes during swallowing, allowing the food to pass into the esophagus at the base of the tongue
- Conspicuous Glottis: paired, fleshy laryngeal prominences that open and close to form the CG, no epiglottis

Glomerulus: 1.cluster of nerves or blood vessels; a tightly packed cluster of blood vessels, nerve fibers, or other cells; 2. round structure in the kidney: a round cluster of interconnected capillaries found in the cortex of a kidney, which remove body waste to be excreted as urine

Glomerulopathy: disease or condition of the blood vessels or capillaries

Gluconeogen’isis:  production of glucose by the decomposition of glycogen (storage of starch in liver), sugar

Glucose: simple sugar in foods, especially fruit; found in the blood; major source of energy for most living organisms

Going light: losing weight

Goit’ogens-goiter producing substances

Gonads: primary sexual organs, testes and ovary, which produce sperm and eggs

Gonys: (go’nis) the lowermost ridge along the tip of the lower mandible of a bird’s bill, at the junction of the two joined halves, esp. prominent in gulls; lower edge of mandible;

Gout: depression, lameness, joint swelling (redness and white substance in joints) Nitrogen is major waste product in urates, gives urates white pasty look; when kidneys don’t function well urates are built up in blood and deposited into joints and around heart, liver and other internal organs;
- Articular gout: in joints
- Visceral gout is inside body. Cause: old age, advanced kidney disease, severe dehydration
- Diagnosis: urine, flood tests confirm kidney disease
- Treatment: fluid therapy, electrolyte therapy, allopurinol dissolves urates and aids in excretion, poor prognosis

Graduated: feathers successively shorter from center to outside (tail)

Gram’s stain: method of differential staining of bacteria, devised by Hans Gram, identifies bacteria; gram + bacteria stain violet; gram-negative stain red or pink

Gram negative: A classification of bacteria based upon their lack of retention of a certain stain in the laboratory. The staining quality is based on the structure of the cell wall surrounding the bacteria. This structure of the cell wall influences which antibiotics will kill the bacteria. This laboratory staining method was developed by Hans Gram in 1884.

Gram positive: A classification of bacteria based upon their uptake of a certain stain in the laboratory. The staining quality is based on the structure of the cell wall surrounding the bacteria. This structure of the cell wall influences which antibiotics will kill the bacteria. This laboratory staining method was developed by Hans Gram in 1884.

Granulated tissue: having a grainy texture

Granuloma: a tumor-like mass or nodule consisting of actively growing capillary buds, fibroblasts and several types of white blood cells; may be caused by a chronic inflammatory process associated with infectious disease, by invasion of a foreign body, or by the healing process of a large, gaping wound.

Gular sac: bare skin on throat and base of mandible


Hallux: long hind toe, also called “first toe”

Hatch year: (HY): the age designation of a young bird that is still in its first calendar year of life; on Dec. 31 it’s still an HY bird, on Jan 1 it becomes a second-year (SY) bird ; Juvenile: young bird in its hatch year
- After-hatch year (AHY): bird is in at least its second calendar year, but whether it is its second year or older cannot be determined
- After-second year: bird known to be at least in its third calendar year or older

Helminths: parasitic worm; e.g., a fluke, nematode or tapeworm

Helminthi’asis: the disease

Hematoche’zia: hi mat/o kee’zha: passage of bloody stools

Hematology: science dealing with structure of blood and blood-forming tissues, such as bone marrow and with their function in sickness and health

Hemolysis: rupture of red blood cells, causing the hemoglobin contained in them to be released into the blood plasma

Hematology: science dealing with the structure of blood and blood-forming tissues, such as bone marrow, and with their function in sickness and health

Hematoma: A mass of blood within the tissues. Generally, the result of trauma to the blood vessels or abnormal blood clotting

Hematopoisis: production of red and white blood cells and platelets, occurring primarily in bone marrow

Hematur’ia: blood in urine, kidney, liver disease

Hemoglobin: the oxygen-carrying pigment of red blood cells that gives them their red color and serves to convey oxygen to the tissues

Hemoglobinur’ia: presence of hemoglobin pigment in the urine; blood in the urine

Hemolysis/hemotolysis: the breaking down of red blood cells resulting in release of hemoglobin into blood plasma

Hemorrhage: escaping of blood

Hemostasis: the stoppage of bleeding; the stoppage of the circulation of blood in a part of the body; stagnation of blood in a part

Hemostatic system: controls the stopping or slowing down the flow of blood; hemostatic agent: an agent that stops or slows down the flow of blood

Hepatic peritoneal cavities: liver is encapsulated within 2 paired peritoneal cavities, ventral and dorsal (VHPC)

Hepatomeg’aly: enlargement of the liver, due to liver disease or heart failure

Hepato’pathies: diseases of the liver

Hepatotoxicity: poisonous to the liver

Heptosplenomegaly: enlarged spleen and liver

Heterophil: having an affinity for an antigen other than a specific antigen

High titer vaccine: A modified live vaccine that contains a higher number of virus particles than the 'average' vaccine. High titer vaccines can generally elicit an immune system response in young animals that have a maternal antibody level that would prevent them from responding to an 'average' vaccine. 

Histology: study of microscopic structure of tissues

Histopathology: study of a disease’s  effects upon the individual cell or group of cells; microscopic study of tissue changes caused by disease, done by a pathologist

Holocrine: pertaining to a gland releasing a secretion that is a product of disintegrating cells; the secretion released by such a gland

Homeotherm/homeothermic/homiothermic: an organism with a stable, independent body temperature; an organism whose stable body temperature is generally independent of the temperature of its surrounding environment

Homologous: having the same or similar relation, as in structure; pertaining to an antigen and its specific antibody

Hormone: Chemical substance produced by one part of the body which serves as a messenger to or regulator of the processes of another part of the body.

Host-specific: virus, bacteria or parasite that cause disease in only one species or genus

Humor: body fluid, e.g., blood, lymph, bile, humoral immunity

Hydrolysis: chemical decomposition in which a compound is split into other compounds by reacting with water

Hydroscope/hydroscopic: an optical instrument constructed from a series of mirrors encased in a tube, used for observing objects deep beneath the surface of a body of water

Hyoid bone: bone extending into the back of the tongue; allows them to extend their tongues

Hyperechoic walls/hypochoic: too many or too few sound waves

Hyperemia: abnormally large amount of blood in any body part

Hyperesthesia: Abnormal sensitivity to touch, pain, or other sensory stimuli. 

Hyperkeratonic scales: thickening of the horny layer of skin

Hyperkeratosis: thickening of horny layer of keratin, beak and feet

Hyperplasia: abnormal multiplication of cells; enlargement of a part due to an increase of its cells

Hyperplasic: Adj. form of hyperplasia

Hyperplastic bone marrow: bone marrow with an excessive amount of normal blood cell-producing tissue; leads to anemia; bone marrow unable to supply red blood cells fast enough for normal body requirements

Hyperpnea: deep, rapid respiration

Hyperthermia: higher than normal body temperatures;

Hypertonic: a body part such as a muscle or artery that is under unusually high tension; a fluid that has a higher osmotic pressure than another fluid

Hypertrophy: abnormal growth or enlargement of organ or tissue

Hypertrophic osteopathy: excessive growth, abnormal enlargement, manipulation of muscle and bones to promote structural integrity

Hypopenae: afterfeathers

Hypopnea: Slow and shallow breathing

Hypoproteinemia: abnormally low concentration of protein in the blood

Hyporachis: feather shaft

Hypothermia: lower than normal body temperatures; bird will soon die if it can’t bring its body temp back to normal.

Hypovitaminosis: disorders caused by less than desired amounts of vitamins

Hypervitaminosis: too much vitamin in body

Hypovolemic (shock): type of shock caused by reduced blood volume, as in massive bleeding or dehydration

Hypoxemia/hypoxemic: inadequate oxygen in the blood


Iatrogenic fractures: medical disorder caused by error of physician

Iatrogenic perforation: tear caused by doctor error

Idiopathic: disease of unknown origin Acquired disease: caused by disorder, injury or tumor

Idiopathic/Idiopathic prolapse; prolapse:  falling down of an organ from its original position; of unknown causes

Ileum: the third and lowest division of the small intestine, extending from the jejunum to the cecum

Ileus: intestinal obstruction characterized by lack of peristalsis and leading to severe colicky pain and vomiting

Immediate or Proximate cause: in bird behavior a particular stimulus in a bird’s environment that causes it to release an automatic behavioral response.

Immune system: group of lymphatic tissues involved in lymphocyte production, immune responses, or both; such tissues include the thymus, bursa of Fabricus, lymphatic nodules and nodes and spleen

Immune tolerance: failure to produce antigens against a pathogen; self-antigens are body parts, foreign antigens are outside the body

Immunity: protected from a disease, especially an infectious disease; usually a result of having been exposed to an antigenic substance peculiar to the disease while infected, or by having been immunized with a vaccine which stimulates the production of specific antibodies.

Immuno-suppressed: defective immune response; inability to produce antibodies against disease or to mount an immune response that would normally overcome disease challenge

Imperforate: separate by a septum (nostrils) Perforate: continuous with other side (nostrils)

Inappetence: inappentency, inappetent lack of appetite

Incised: cut with a sharp instrument such as a scalpel

Incumbent: at same level, resting or leaning on something

Incubation: 1. process by which eggs are kept at proper temperature for embryonic development; sitting on the eggs; 2.provision of proper conditions for growth and development, as for bacterial or tissue cultures; 3.development of an infectious disease, from time of entry of the pathogen to appearance of the first clinical signs;

Incubation period: The time between the exposure to a disease-causing agent, and the clinical onset of signs of the disease; provision of proper conditions for growth and development, as for bacterial or tissue cultures; development of an infectious disease from time of entry of the pathogen to appearance of the fist clinical signs; period of time required for a fertilized egg to develop an hatch

Infection: The invasion and replication of microorganisms in tissues of the body; generally causes disease or local inflammation.

Index case: initial individual whose condition or disease led to an investigation of a disease outbreak or hereditary condition

Infundibulum: funnel-like entrance of the female’s bird’s reproductive tract; egg leaves ovary and enters the infundibulum; opening into the
oviduct; sperm meet egg in infundibulum

Infundibular cleft: a small slit located behind the choanal slit, the opening to the middle ears, connected by a tube, the pharyngotympanic tube. Middle ear infections cause the cleft to be red and swollen

Infectivity: virulence or strength of the pathogenic bacteria

Infraorbital sinus: sinus below/behind the eye

Inner secondaries: groups of secondary feathers located closest to the body with respect to the outer secondary coverts

Infraorbital: below the eye

Influenza: inflammation of respiratory tract caused by disease organism; very rare in pet birds;

Ingluvies: crop

Inner Primaries: group of feathers closest to the body on the wing; covered partially by the secondaries (shorter, upper "arm" feathers)

Inner wing: similar to inner arm of human; includes shoulder, secondaries (shorter, upper "arm" feathers) and secondary coverts

Inoculation: injection of vaccine or bacterin  (a vaccine prepared from killed bacteria)

Inspissa’ted/inspis’sate: to condense; to become thicker in consistency, or cause something to thicken, especially by boiling or evaporation

Insufflation: inserting air into an organ

Insuffla’tins: (insuff’late) to blow or breathe something into some opening or upon some part of the body

Integument: natural covering, skin

Intercostal region: located between the ribs

Interramel region or interramel space: fleshy area under lower mandible holds tongue and related structures

Interscapular region: between scapulas or shoulder blades

Intracellular: within a cell or group of cells

Intradermal: within the skin

Intraosseously: into or within the bone

Intraosseous injections: into the bone using a cannula; fluids or drug administration

Intraosseous cannula (can’nula/lae): into the bone; a flexible tube with a sharp-pointed part at one end that is inserted into a duct, vein, or cavity in order to drain away fluid or to administer drugs.

Intracellular: within a cell or group of cells

Intumescence: swelling up, swollen mass

Intussusception: a sliding of a portion of a tubular organ into another portion, especially a condition of the bowel in which this happens, creating swelling that leads to obstruction

Ipsilateral/contralateral: being on or affecting the same side of the body, on the opposite side of the body, or that acts in conjunction with such a part

Iris: colored part of the eye, located around the pupil; does not play a role in vision

Ischemic/ischemia: local deficiency of blood supply due to obstruction to blood flow

Ischia’tic nerve: ischem’ia: local deficiency of the blood supply produced by vasoconstriction or local obstacles to the arterial flow

Isoflurane anesthesia: volatile, halogenated ether

Isolation area: area or caging constructed in manner to prevent spread of contagious conditions. Area or cage should have ventilation system that prevents commingling of air from isolation area with air in healthy animal area


Joint effusion: fluid escaping from the joint

Jugulum: ventral part of the neck under the beak; jugulum and gular region comprise the throat; also called foreneck or throat patch.

Juvenile plumage: feathers worn by birds after they have molted their natal down; consists of the first true contour feathers


Keratin: hard protein that forms scales and claws and is the primary structural component of mature feathers or other horny body parts; insoluble in water, weak acids or alkalis, and unaffected by most protein-dissolving enzymes

Keratinocytes: keratin cells

Keratoma (tosis) disease characterized by having a horny growth on the skin
Kerfs: shallow grooves cut horizontally below the entrance hole on the interior of the front of a nest box; provide footholds for nestlings and adults as they climb up to the hole

Klebsiella: one of nastiest of gram negatives; Claforan is best antibiotic

Knee: joint in middle part of leg; strong leg bones and knees to take-off and land
- Dislocated: mostly in young birds before fledging, legs twisted and deformed from knee down, Cause: congenital birth defect, Treatment: splints, bandaging, surgery, usually unsuccessful, remove parents from breeding program


Lacrimal duct: tear duct

Lamellate: coarse or fine parallel ridges or plates at cutting edge of beak

Laryngeal mound: a conspicuous mound in the throat at the entrance of the larynx.

LDH: enzyme found in liver, muscle, heart, etc. released with damage, used to measure degree of pathologic condition; lactic dehydrogenase

Latent infection: also known as carrier state. An animal is infected with a disease and is potentially infectious but not showing signs of disease

Leading edge of wing is the first area from a frontal position when the bird is in flight; slightly curved and feathered; where the feathers are attached

Legs: support the bird; proportionally, the legs are extremely strong in order to land and take off

Leg bones: modified; thigh bone (femur) same as mammals; knee joint (patella) follows below femur; next bone has several bones fused to form tibiotarsus bone; in it ankle bones fused with the bones of the arch of the food to form one long bone; small fibula bone present; next joint is intertarsal joint, humans don’t have one; bone below that joint is the tarsometarasus, consists of fused bones. Elongated tarsometatarsus looks like the shin bone, so you think that the joint should bend like  a knee, but the knee is up higher, in the feathered area of the leg, and does bend the same as human’s does

Lesion: damage to organ or tissue

Lesser secondary coverts: short feathers overlying the median secondary covert on the top of the wing; near the shoulder and can be seen as the first row of feathers on the bird’s wing; also called marginal coverts

Lethargy: lack of energy, drowsy, dull, sluggish or inactive

Leukocytes: white blood cells, Leukocyte Morphology: refers to the structure, good or bad, of the white cells; gives an idea of how sick the bird is

Leukocytosis: increase in number of white blood cells

Leukopenia: decreased number of white blood cells

Lice: parasitic, wingless insects; Nits: eggs of lice

Lingual Nail: stiff, pliable, keratinized cuticle on top of tongue, beta keratin filaments arranged like scutellate scales

Lipemia: excessive amounts of fat in blood

Lipogenesis: cause of fat deposit

Lipogenic: produced or caused by fat

Lipoma: fatty benign tumor

Lysed cells:  cause dissolution or destruction of cells by lysins

Lysin: an antibody causing the disintegration of erythrocytes or bacterial cells; ear wax is a mass of partially lysed cells and traps particles to keep the ear canal clear

Liver failure: weakness, wobbly gait, difficulty breathing, swollen, fluid-filled abdomen, swollen liver, end-stage disease; liver damaged by cancer, fat infiltration from high fat diet, cirrhosis from chronic exposure to poisons; x-rays, blood tests identify cause and severity of problem; treatment usually euthenization because by the time symptoms occur it’s untreatable.

Lobate: each toe (2, 3, 4) is edged with separate webbing as in American coot

Lobe: roundish projection or division, e.g., ear

Lore: area between eye and beak

Lumen: cavity or channel within a tube or tubular organ, such as blood vessel or intestine

Lutino cockatiel syndrome:
- Baldness, on crown
- Hemophilia: uncontrolled bleeding
- More prone to disease, appear mentally retarded or undeveloped
- Lack of coordination, appears drunk
- Falls off perch at night
- Bruising/bleeding wing tips, abdomen, pectoral muscles, prone to trauma and falling
- many genetic problems

Luxation (fracture) loosening or relaxing, being relaxed, to displace the bones of a joint

Lycine: betaine, buckthorne

Lymphocytes: second most important white cell; responsible for antibody function

Lymphoepithelial system: composed of mucosa associated with lymphatic tissue, mucous covers cellular receptors for bacteria and viruses


Macaw “Acne”: Small swellings on face caused by small,  ingrown feathers on face and eyelids, simple surgery to release trapped feathers; antibiotic injections, cortico-steroids needed if bird rubs and scratches affected sites.

Macrophages -phage: large white blood cell in bloodstream that ingests foreign particles and infectious microorganisms by phagocytosis; occurring mostly in connective tissue and in bloodstream

Malaise: discomfort, uneasiness or weakness often indicative of infection

Malar stripe: area below the eye and beak, parallel to the throat; located on the sides of the chin and stretches downward; brightly colored; whisker, mustache or malar streak

Malnutrition: reduced state of health brought about by insufficient or improper diet

Mandibular prognathism: mandible that projects forward to a marked degree
Mandibular ramus: prong-like projection from the beak on the posterior side; not present in all species.

Mantle: upper surface of the back and wings covered with shorter feathers

Manus: hand part of the wing; many bones fused; skeleton simplified; bones of wrist consolidated, only three “fingers.” Smallest is alula, other two called the major and minor digit; has fewer phalanges than human;

Marginal coverts: feathers overlying the base of the median secondary coverts and also called lesser secondary coverts or shoulder; at the top edge of the wing closest to the body of the bird

Mate guarding: following of the female by its mate to prevent her access to other males and their access to her; assures he is the father of at least some of the young in his nest

Mea’tus: opening in a bone or bony structure, like ear or nose

Megabacteria: pathogenic organism, large Gram+ rod, weight loss

Medium/Media: materials used on which microorganisms are cultured

Membrane: thin, flexible layer of tissue connecting, covering or separating various parts or organs

Median secondary coverts: feathers on the wing covering the bases of the greater secondary coverts; tips can often be slightly lighter in color or white, giving the wing an illusion of being horizontally “striped.”

Medulla: the marrow of the bones, soft, marrowlike center of an organ, as the kidney or adrenal gland

Medullary: pertaining to, consisting of, or resembling the medulla of an organ or medulla oblongata in the brain

Medullary bone density: bone marrow

Medullary bone formation: (hyperostosis, osteomyelosclerosis) controlled by hormones, seen in wing and leg bones

Medullary hyperostosis: abnormal development of bony tissue in the medulla of an organ

Melena: Discharge of heavy black stool, hemorrhage into intestinal tract, blood in stool
Mesenchyme: skin cells of mesodermal (middle dermis) origin capable of developing into connective tissues, blood, lymphatic and blood vessels

Mes’entery: the membrane, consisting of a double layer of peritoneum (membrane lining the abdominal cavity and investing its viscera) , that invests the intestines, attaching them to the posterior wall of the abdomen, maintaining them in position in the abdominal cavity, and supplying them with blood vessels, nerves, and lymphatics, esp. the part of this membrane investing the ileum and jejunum.

Metabolic acidosis:  a blood condition in which the bicarbonate concentration is below normal

Metabolism: the sum of the physical and chemical processes in an organism, by which its material substance is produced, maintained and destroyed, and by which energy is made available; all the chemical processes that take place in the cells and tissues of the body

Microbe: microorganism, especially one that causes disease

Microorganism: microscopic organism such as bacteria, fungi, protozoa, and viruses

Microsurgery: repair of minute structures with the aid of microscope and very small instruments

Mites: (Scaly Face) tiny parasitic arachnids found in or on feathers and skin; mite infestation causes abnormal tissue growth around face and beak;  treatment: Ivermectin
Red Mites: skin irritation, pale legs and beak (anemia), scratching, poor feather condition, large number, hide everywhere, walls, rugs, etc., come out at night and suck blood, leads to death; Treatment: dust bird and cage and nestig material with Carbaryl or pyrethrin, treat bird

Mitosis: type of cell division by which body grows and cells are replaced Mitotic: the type of cell division in which each daughter cell contains the same number of chromosomes as the parent cell;  the process by which the body grows and cells (other than reproductive cells) are replaced

Mobbing: group of birds swoop and dash at a potential predator; give alarm calls which attract additional birds; distracts the predator, drives it away, or lets it know it has been detected

Molt: process of shedding all or part of the feather coat and replacing it with new growth

Monocytes: white cells associated with chronic disease, especially Psittacosis, Aspergillosos, and Tuberculosis

Monogastrics: single stomach

Mon’omeric: single, unjoined organic molecule; a relatively light, simple organic molecule that can join in long chains with other molecules to form a more complex molecule or polymer

Monomorphic: male and female have same plumage and coloration; sexes cannot be distinguished by observing external characteristics (see dimorphic)

Mortality: death; factors causing it

Motility: Movement, e.g., intestinal motility is the muscular contractions of the intestines which move the food from the stomach to the anus; motility time: time it takes food to process and be excreted

Mucosa: Specialized membrane which covers various passages and cavities exposed to the air, such as the mouth, nose, inner portion of the eyelids, vagina. Examination of the mucous membranes can provide important information: if they are dry, the animal is likely dehydrated; pale, and may be anemic or in shock; yellow, and the animal is said to jaundiced due to accumulation of waste products which should have  been eliminated by the liver. From mucous membrane

Mucolitic: pertaining to enzymes that break down mucous

Mucoprotein: a protein that yields carbohydrates as well as amino acids in hydrolysis: chemical decomposition in which a compound is split into other compounds by reacting with water.

Mucous membrane: a membrane lining all body passages that communicate with the air, the glands of which secrete mucous.

Mucous: viscous, protective substance secreted by the glands of the mucous membrane

Multilobulated: many lobules, small lobe or division of lobe

Muscle petechiation: signs: weakness, dazed look, cardiac symptoms, pallor in mucous membranes, Blood tests,  Treatments: fluid replacement B Vitamins, Vit. K, D2, calcium, antibiotics

Mycoplasma: bacteria lacking true cell wall; can cause respiratory disease

Mycoplasmal: minute organism, like bacterium; a microorganism of a genus considered to be the smallest known living cells. Some species cause respiratory diseases in animals and humans. Regarded by some as primitive bacteria, they need sterols such as cholesterol for growth; parasitic microorganism, causes pneumonia and urinary tract infections
Mycotic/mycosis: fungal disease, mycotic drug kills fungus, e.g. Nyzoral

Mycotoxins: compound produced by byproducts of molds; poisonous substances emitted by fungi

Myeloid system: spinal cord or marrow

Myocardial fibrosis: heart muscle scarring from chronic disease

Myxoma: soft tumor composed of connective tissue and mucous

Myxomatosis: condition of many myxomas

Myxomatous: a benign tumor composed of mucus and gelatinous material embedded in connective tissue, typically in the heart where it can obstruct blood flow and lead to sudden unconsciousness


Naris/nares: nostrils

Nasal septum: partition or membrane between 2 cavities or soft masses of tissue

Nasal canthus: in the inner corner of the eye; same location as corner of human eye closest to the nose

Nasal fossa: depression in which the bird’s nostril is located; the openings into the nares

Nebulization: medication used as a spray, inhaled, for bacterial or fungal respiratory infections, esp. upper respiratory, topical, localized treatment of internal air sac and is not dependent on absorption

Neck: allows bird to move his head to increase its visual area without moving body; different species have different lengths; holds cervical vertebrae, which are the bones that surround the spinal cord; birds have 11 to 25 cervical vertebrae, depending on the length of the neck; minimum length of the neck is long enough to enable the bird to reach Uropygial gland so it can preen; neck is often but not always proportional to the length of legs; esophagus and trachea are found in neck, also jugular veins (often used for venipuncture.) Forms an S curve, protrudes forward in front, above level of crop, because of having more vertebrae than humans; it is extremely flexible, mobile and strong

Necrotic/necrosis:death of cells in a tissue or organ caused by disease or injury; necrobiosis

Nematodes: parasitic  round worms

Neonate: newborn bird state which lasts till bird opens eyes and begins to quill out

Neoplasia: tumor growth or formation and growth of new tissue

Neoplasm: new and abnormal growth; may be benign or malignant

Nephrocalcinosis: calcification of kidneys from Hypervitaminosis D

Nest cup: depression in the nest to hold the eggs

Newcastle Disease, virus, poultry and wild birds, etiology is paramyxovirus, attacks GI, Respiratory and nervous systems, in psittacines high susceptibility, omnivores most sensitive

Nictitating membrane: third eyelid, drawn over the eye to clean it; see “eyelid;” vertical, semi-transparent fold under the eyelid; used for protection; has its own moisturizing system similar to tear ducts; can be closed to protect parent from baby’s beaks

Nidus: a place in an organism where another organism can live or breed

Nonpathogenic: Not causing disease. Some bacteria, such as those that normally live in an animal's intestines, are nonpathogenic.

Nosoco’mial: infections contracted from being hospitalized

Nonseptic: A condition not caused by an infection. For example, septic arthritis is caused by an infection with bacteria, yeast, or other agent; a case of nonseptic arthritis may be caused by injury or cancer.

Nostrils: the two openings on the cere

Notarium: term for vertebrae in thoracic region; from shoulder to lower back

Notched: with a notch, like a pointed bite taken out of it, as in the tail or beak


Obtuse: not very sharply pointed

Occlude, Occlusion,Occluding: to stop up: to block or stop up something such as a passage; to cut off or prevent the flow or passage of something such as light or liquid 

Ocular: pertaining to the eye

Oglets: beginnings of the pinfeather, keratin sheath

Oncotic: like a tumor or mass

Oocyte: type of gametocyte that produces ova (eggs); found in protozoa, e.g. Giardia

Opaqueness: clouding of normally transparent object

Oper’culum: keratinized plate on inside of the nostril (cere); small, round, brownish structure, can be obstructed by rhinoliths: a mass formed of desiccated secretions and debris

Opisthotonos: spasm in which head and tail or heels are bent backward and body bowed forward; seen in poisoning, such as strychnine, infectious diseases such as tetanus, infections of central nervous system and some types of brain lesions

Organic matter: animal or vegetable tissues

Oropharynx: the part of the pharynx between the mouth and glottis (opening at top of pharynx) contains the tongue, glottis, choana, palate, salivary glands, esophagus, opening of pharyngotympanic tubes (ear tubes) and laryngeal mound.
- Examination of the oropharynx can tell about overall health of bird, can indicate if there is malnutrition, Vitamin A deficiency, bacterial or yeast infection or middle ear infections; symptoms: choana swollen, papillae blunted or absent, infundibular cleft red, abscesses present, thick, white ropy mucus is present; internal papillomatous disease (papillomas) can occur through GI tract, and lesions may be present in the oropharynx; look like small, pink, wart-like lesions. 

Osmosis: diffusion of fluids through membranes

Osmolality: ability to be absorbed through membranes or porous partitions, gradual absorption

Ossification: process of bone formation; the natural process of forming bone; hardening of soft tissue as a result of impregnation with calcium salts; bony mass or deposit of bony material in the body

Osteoblast: a bone-forming cell

Osteoblastic tumors, on elastic bone lesions

Osteology: branch of anatomy dealing with skeleton

Osteolysis: breaking down, decomposition of bone (bone-lysis)

Osteomyelitis: An inflammation and infection of the bone

Otitis: inflammation of the ear

Otitis externa: external ear infection

Ototoxic: Destructive to the structures of the ear. Oto: pertaining to the ear

Outer Primaries: on the wing farthest from the body, longest feathers on the wing

Outer secondaries: the secondary feathers on the wing furthest from the body

Outer tail feathers: feathers farthest from the body; the ones that fan out the farthest

Outer wing: encompasses the alula and primary feathers

Ovary: female gonad; matures and releases egg cells throughout the breeding season during ovulation; only left ovary is functional and enlarges greatly during the breeding season; have only one to lighten it for flight

Ovum: egg released from the ovary, before or after fertilization; after breaking free of the ovary it takes on nutrients (yolk) and  it enters the infundibulum; there it meets with sperm; the vitelline membrane surrounding the yolk will allow one sperm cell to penetrate it and fertilization takes place; germinal disk: exact spot where life begins to grow; the small white spot evident on most egg yolks; immediately after fertilization takes place cellular division begins; as it travels down the oviduct, glands that secrete the nutrients to create the albumen, shell membranes and eventually the shell, the other components of the egg are added until it reaches the uterus or “shell gland;”shell  hardens in the uterus and the chalazae, outer shell membrane, inner shell membrane, airspace, thin albumen, thick albumen are formed

Distal Oviduct: uterus

Oxygen therapy, uses incubators to monitor heart and humidity, face mask for short term, used to stabilize birds, for anemia, shock, dyspnea, (labored breathing)


P.C.V. packed cell volume in birds; percentage of the volume of whole, unclotted blood occupied by red blood cells

Pacheco’s virus/disease: sudden death in a few days, depression, ruffled feathers, yellow/green diarrhea, polyuria, polydipsia; cause: herpes virus carried by conures, no treatment, passed in feces; liver disease, named after its discoverer

Palatine: of or near the palate; palatal, palatine bones

Palmate: completely webbed, front toes (3 toes) connected as in ducks) semipalmate: webbed only at base (toes), anterior toes are joined part way by a small webbing; also known as “half-webbed.” Totipalmate: all 4 toes connected by web

Palpation: to examine with hands or fingers

Palpebral conjunctiva: membrane under eyelid: a delicate mucous membrane that covers the internal part of the eyelid and is attached to the cornea

Pamprodactyl: all four toes in front, as in swifts

Pancreatic exocrine insufficiency: malabsorption due to insufficient pancreatic enzymes; pancreas not secreting enough enzymes through pancreatic duct; weight loss, bulky, pale droppings

Pancreatitis: infection caused by bacteria, virus or Chlamydia infection;  Vit E and selenium needed

Pantagium/pantagia: wing membrane, fold of skin; flat, membrane-like structures of the skin in areas where wings, legs, tail and neck meet body; these and ventral tail region are common sites for ulcerative dermatitis

Papillae: small, nipple-like projections on tongue and in choanal slit; these are normally found at the edges behind the choanal slit; others are found pointing towards the back of the throat in the oropharynx;

Papillomatosis: warty growths on feet, uropygial gland, corners and inside mouth, around beak, wings, eyelids, cloaca, intestines. Virus? Cause of cloacal prolapsed, mostly in macaws and amazons, papillomas hanging out, surgery if possible in area without damage to other structures, seem to go away on their own but become internal

Parabronchi: tiny tubes in bird lungs through which air moves in a one-way flow; oxygen and carbon dioxide are exchanged in microscopic capillaries in spaces within parabronchial walls

Paralysis syndrome: trembling, wobbly gait, incoordination, reluctance to walk, lies on floor of cage, abnormal head movements, mostly in cockatiels; cause: Vit. E deficiency, selenium deficiency, related to intestinal damage caused by giardia infection; injections of Vit E and Selenium, helps in early stages, later not successful

Parasite: organism that feeds upon the tissues of another, host organism; lives either outside (ectoparasite) or within the hosts; body (endoparasite); killed by parasiticide
Subcutaneous parasite: penetrates the outer body tissues of host and lives there
Parasitemia: presence of parasites in blood

Parenteral: A term used to describe the administration of a drug by means other than by mouth. As for antibiotics; can be subcutaneous, intramuscular or intravenous injection

Pare’sis (leg): partial motor paralysis

Peritonitis: inflammation of peritoneum, membrane that lines the walls of the abdominal cavity

Particulate: small particle

Passerines: songbirds

Patagium: wing membrane, extendable fold of skin where wing meets body Propatagium: elastic triangular fold of skin on the leading edge of the wing; tattoos placed there and surgical sexing done there
- Metapatagium: after or behind the patagium

Pathogen/pathogenic: organism that causes disease; bacteria, protozoa, virus, fungus, etc.
Pathogenesis: production and development of disease

Pathology: study of the nature and cause of disease, which involves changes in structure and function; condition produced by disease

Pathotype: to ascertain the kind of blood or tissue sample of a disease

Paucity: scarcity

Pectoralis muscles: largest and most powerful muscles in flying bird’s body; contractions power the wings’ downstrokes

Penna: contour feather

Pennaceous: having the texture of a penna as opposed to a downy feather

Peracute: extremely acute, of only a few hours’ duration

Percutaneous: medicine that is administered or absorbed through the skin

Paresis/Paretic: partial motor paralysis

Perforation: the formation of a hole in an organ, tissue or tube, usually as a consequence of disease

Pericardial effusion: escape of fluid around heart

Periostium (periostial): the normal investment of bone, consisting of a dense, fibrous outer layer, to which muscles attach, and a more delicate, inner layer capable of forming bone

Periostitis: inflammation of periosteum

Peristalsis: progressive waves of contractions and relaxations of the tubular muscular system, esp. the alimentary canal, by which the contents are forced through the system

Peritonitis: inflammation of the peritoneum, pain, tenderness in abdomen, vomiting, constipation, fever

Petechiation/Pete’chia: a minute, round, non-raised hemorrhage in the skin or in a mucous or serous membrane

Phagocyte: white blood cell that absorbs foreign bodies in blood stream

Phagocy’tic: any cell that ingests or destroys foreign particles, bacteria or cell debris;                                Cytosis: act of destroying the particles

Pharyngo-tympanic tubes: Eustachian tubes

Pin feather: newly developing feather

Pinna;pinnae: feather, wing, or wing-like part; elongated feathers projecting from the upper body area, generally the neck or head, e.g., prairie chicken—used for courtship

Pipping: embryo punctures a small hole in shell when about to hatch

Plasma: fluid portion of the blood in which red and white blood cells are suspended, as well as thrombocytes; not the serum, which is plasma from which the red and white blood cells have been removed

Plasmid: small, independent circle of DNA;  a small circle of DNA that replicates itself independently of chromosomal DNA, especially in the cells of bacteria. Plasmids often contain genes for drug resistance and are used in genetic engineering, since they can be transmitted between bacteria of the same and different species.

Plumage: bird’s entire feather coat; set of feathers produced by a molt

Plume: down feather

Plumulaceous: having the texture of a down feather

Plumy: having plumes or feathers

Pneumatic bone: hollow, no marrow, allows bird to be light enough for flight; pelvic bones, some ribs, most vertebra, some in head, humorous and femur all have large, air-filled medullary canals that are involved with the respiratory cycle during flight;
wide medulla (central cavity) and  thin cortex (outer wall);

Polex: thumb of the first digit of the wing, the alula

Polycythemia: abnormally high number of red blood cells

Polyoma virus:
- in young birds: enlarged abdomen, crop stasis, poor motility, bruising under skin, death in 2-3 days.
- In older birds: abnormal rectrices and remiges, weight loss, poor growth; frequent cause of death in young birds, breeding conditions poor, no treatment

Polyostotic hyperostosis: abnormal development of bone tissue,

Polycythemia: abnormally high number of red blood cells

Polyderma: infection of the skin

Polydipsia: excessive thirst

Polyostotic hyperostosis: radiographic evidence suggestive of hyperestrogenism that appears as calcification of the medullary spaces of the long bones, particularly of the femur and tibia

Polyp: A small growth from mucous membranes such as those lining the nasal cavity and intestinal tract.

Polyphasia: excessive indigestion of food

Polyuria: formation and excretion of high volume of urine

Portal circulation: circulation of blood from digestive tract and spleen to the liver via the portal vein and subsequently, out of the liver via the hepatic vein

Potable: water that is free of pollutants and suitable to drink

Pox virus:
- young birds mostly, virus can live on fomites for 2 years, different symptoms depending on where virus attacks; causes pustules in or around eye, lesions on skin and in mouth
- Skin: Dry Pox: red, oozing sores becoming large and scabby bacteria and fungi enter to be secondary infections
- Wet Pox: Gray/brown accumulations of cheesy pus in mouth, throat, windpipe; If cheesy pus removed leads to bleeding, can’t swallow or breathe, other diseases similar
- Septicaemia Pox: sudden onset of sleeping, ruffled feathers heavy breathing, death within 3 days.

Pathology: lungs hemorrhage, fat in liver, inflammation in small intestines, rarely seen in psittacines

Prandial: pertaining to a meal

Precursor: substance from which another, more active or mature substance, is formed

Preening: feather maintenance; bird grasps a feather near base, nibbles along the shaft toward the tip with a quivering motion; this cleans and smoothes the feather; use oil from Uropygial gland and spreads it on feathers as they preen

Present’: how a disease appears as symptoms

Primaries: 9-10 or more outermost (longest) flight feathers, attached to hand of wing

Primary coverts: short feathers that cover and protect the primary flight feathers

Primary numbering: numbering system which assigns number to each primary feather for identification

Pro’bang: a long, slender, elastic rod with a sponge, ball or the like at the end, to be introduced into the esophagus or larynx as for removing foreign bodies, or for introducing medication

Proctodeum: (proctodea) a depression of the ectoderm of the anal region of a young embryo which develops into part of the anal canal

Prolapse: falling down or slipping out of place of an organ from its original position

Prophylactic: preventive treatment

Proprioceptive: a receptor located in subcutaneous tissues, as muscles, tendons and joints that responds to stimuli produced within the body; pertaining to proprioceptors, the stimuli acting upon them or the nerve impulses initiated by them

Proprioception: perception governed by proprioceptors, as awareness of the position of one’s own body

Prosthesis: artificial substitute for a missing body part

Proteins: complex molecules composed of strings of amino acids; main building blocks of all living organisms; also act as enzymes, assisting chemical reactions

Protocol: plan for a course of treatment or scientific experiment

Protozoa: one-celled (smallest) animals that often cause disease, e.g. (coccidia); some live in colonies; reproduction by fission, free- living, some commensalistic or parasitic,  any of the malarial coccidia, Giardia, trichimonosis and hexamitia, etc

Proventriculous: upper, first part of stomach; secretes enzymes that further break down food; gastric stomach

PDD: Proventricular Dilatation Disease: viral disease in which the causative agent (Borna virus) causes inflammation of nerves in the intestinal tract or brain. Ultimately results in enlargement of digestive organs, poor digestive function, wasting and death; no cure or vaccine, but a good treatment plan available using Celebrex.

Pruritis: itching, Prurigo: skin condition of itching

Pseudom’onas:Any of several rod-shaped bacteria which are pathogenic for plants and animals

Psyllium: dietary source of fiber, mild laxative; plant with edible seeds

Psittacine Beak and Feather Disease (PBFD)(circovirus) - no treatment or vaccine, mostly young birds, abnormal feather growth, feather loss, shiny beak from lack of powder down, dusty feathers, feather color changes, infectious, respiratory trouble, conjunctivitis,
diarrhea, abnormal urates, discharges of saliva, droppings, crop contents, Slow onset, weight loss, listlessness, loss of rectrices and remiges, twisted, deformed feathers, usually starts at weaning or first mold, underside of beak rots, can’t eat, but hungry, slow decline, deformed, missing feathers, secondary infections, immune system depressed, cockatoos mostly

Psittacine Pruritic Polyfolliculosis: self-mutilation, itching on rump, neck, shoulders, intense picking to ulcerated areas, feather follicles seem to have more than one feather growing due to damaged feather coming in, looks like multiple feathers, feathers twisted, deformed or under skin. Virus? No treatment completely successful, cortisone injections, lotion, DMSO paint, no cure.

Psittacosis titer: test for presence of Chlamydia psittaci, which causes psittacosis; 2 tests made 3 weeks apart, showing a fourfold increase in titer, indicate active disease

Psychogenic: of mental origin

Pterylae: (ter’ilay) the tracks or rows of feather follicles from which feathers grow, feather track

Pupil: dark, circular, hollow eye passage through which light enters

Pygostyle: tailbone, end-most bone on the spinal column; if damaged male may not be able to copulate successfully with hen


Quarantine area: holding area set apart from other holding areas. Used for temporary isolation of newly-arrived birds pending vet exam.

Quill: stem of feather imbedded in flesh


Rachis: central shaft of feather

Radiograph: X-ray

Radiolucent: penetrable by electromagnetic radiation: interfering very little or not at all with the passage of X-rays and other forms of electromagnetic radiation; almost entirely transparent to radiation, invisible in w-rays and fluoroscopes and photographs

Ramus(i): branch as of a vein or bone

Reabsorption/resorption: process of absorbing again, to take up

Rectrix/rectrices: tail feathers; backmost margin of the tail

Red count: usually refers to PCV measures of red cells to serum after spinning down; measures anemia vs. normal red count

Recumbent: crest that lies flat against the head; Recursive: crest that curves forward

Recurved: curved upward toward tip

Refractory: resisting ordinary methods of treatment

Regurgitation: act of bringing partially digested food from crop back into mouth; Vomiting is from proventriculus

Remix/remiges: large flight feathers

Reovirus: virus which causes hepatitis

Respiratory system: used for breathing and cooling; no sweat glands, birds pant to expel excess heat and stabilize body temps.

Reticulate scales: small, netlike scales (tarsus), covered with a network pattern, marked with lines, composed of alpha- keratin

Reticulocyte: immature red blood cell that contains a network of fibers of ribosomal (cluster of proteins); remains that show up with laboratory staining

Rectrices: (Latin for “rudders”) tail feathers, always paired, one central one; most birds have 6 pairs; tail coverts are small feathers that lie over and under the rectrices

Rhamphotheca: horny covering of upper and lower beak (ramfothee’ka) ; bones of the beak are covered with a thick, modified integument, entirely on the outside and partly in the lining of the mouth, this covering is called the rhamphotheca. It is hard and heavily cornified in most birds, yet still flexible in the flexion zone of the upper beak.
- Maxillary rhamphotheca or rhinotheca: upper mandible, holds cere and nares
- Mandibular rhamphtheca or gnathotheca: lower mandible,

Rhinoliths: a mass formed inside the nares from desiccated secretions or debris; may cause physical obstruction to proper breathing, may disfigure the nares

Rictal: referring to the corners of the mouth

Rictal bristles: short and stiff feathers near the beak

Rictus: base of the beak where the mandibles join; also gape and commissure; gape of the mouth, wide open

Rostrum: bill or beak

Rump: area between upper tail coverts and back of the bird; shorter feathers of same color as body


Salmonella: bacteria causing systemic, intestinal and liver disease. Zoonotic

Sacculitis: sacc’ula/sacculi) the smaller of two sacs in the membrane labyrinth of the inner ear, so an infection in the saccula

Safronine: purplish-red color

Saline: solution of salt (sodium chloride) and sterile water; a solution of .9% salt and water; contains the same proportions of these component as does the blood

Salivary glands: in roof of mouth and floor of mouth and in tongue

Salpingitis: inflammation of salpinx (oviduct) Salpingectomy:  excision of the salpinx

Salpinx: (salpinges): Trumpet-like tube as in Eustachian or fallopian

Sanitation: thorough cleaning to reduce risk of disease

Scapulars: also known as "shoulder feathers" - short feathers in the area where back and wings join; short, soft, same color as back

Scutellate/scuttelation: (scyootell’it/scyootila’tion: with large, transversely-oriented scales (tarsus); a scaly covering, as on a bird’s foot; having large, bony plate; contain beta-keratin

Sebaceous: relating to or producing a waxy, yellowish body oil secretion, sebum

Sebum: an oily substance secreted by the sebaceous glands that lubricates the feathers and skin and gives some protections against bacteria

Secondaries: flight feathers attached to forearm (ulna)
- Greater Secondary coverts: feathers overlying the bases of the secondaries; in some birds the primary coverts are completely covered by them; attached to the “elbow”

Secondary infection: Infection which occurs because the tissue and its natural defenses have been damaged by another condition.

Second intention: a manner or process of healing, as in the healing of a lesion or fracture without granulation, or the healing of a wound by granulation after supportation

Secrete the act or process of separating, elaborating and releasing a substance which fulfills some function within the organism or undergoes excretion

Secretory: pertaining to secretion; performing the process of secretion; a secretory organ, vessel or the like

Selenium:  nonmetallic element: a nonmetallic chemical element that occurs in several forms; incorporated into proteins that make seleno proteins, which are important anti-oxidant enzymes; prevent cellular damage from free radicals: (natural by-products of oxygen metabolism that may contribute to the development of chronic diseases, such as cancer and heart disease);  other seleno proteins help regulate thyroid function and play a role in the immune system.

Self-antigens: normal body cells
- Foreign antigens: antigens unlike the self, autoimmune disease occurs when body becomes intolerant of its own cells

Septic: toxins in blood or tissue

Sentinel birds: birds that are susceptible to a particular disease challenge and may be placed in a potentially contaminated area to detect disease; usual mortality in sentinel bird populations should cause suspicion of disease contagious to all birds in inventory; also, the bird in the flock that keeps watch

Septicemia: invasion and persistence of pathogenic bacteria in the bloodstream; blood poisoning; very serious; can occur from overwhelming infection of any kind; multiply and overwhelm the body, resulting in death; antibiotics used to treat: penacillin, cefotaxime, encofloxacin, trimithoprim, sulfa, doxy and amikacin

Sequela/sequelae: conditions resulting from and following a disease

Seroconvert: to produce specific antibodies in response to the presence of an antigen such as a bacterium or virus; contract virus, is asymptomatic, passes it on, often becomes immune, as in polyoma virus; contract the virus, not become ill, build up immunity but shed the organism to other birds

Serosa/serosae: same as serous membrane

Serous Membrane: a thin, moist transparent membrane that lines the body cavities and surrounds the internal organs; e.g., the peritoneum that lines the abdomen

Serum: watery portion of the blood that results when the blood has been allowed to clot, the clot then being removed

Serrate: with teeth-like saw (cutting edge of beak)

SGOT/SAST: enzyme found in multiple tissues as liver, heart, muscle, etc; used as a liver test in birds and reptiles

Shallow Acinar: (ear) smallest secreting portion of a gland, holocrine sebaceous glands, on fold of skin on floor of ear canal; ear wax traps particles and keeps ear canal clear

Shedding: Shedding (of organisms): A term used to describe the release of organisms (bacteria, protozoa, viruses) into the environment from an infected animal. The organisms may be in the stool, urine, respiratory secretions, or vaginal discharges. The 'shedding' animal may or may not be showing symptoms of disease.

Shigella: nasty gram negative that can make man and animals sick, diarrhea; can kill

Shoulder feathers: short feathers overlying the median secondary coverts on the top of the wing; near the back and can be seen as the first row of feathers on the bird wing; also called marginal coverts and lesser secondary coverts

Signalment: detailed description, distinctive features for identification

Single-brooded: nest only once per nesting season

Sinuses: found in head,(see concha), one sinus is behind the eye, which is why some birds with respiratory illness and sinus infection develop swelling and discharge from the eye.
Sinusitis: inflammation of air passages in skull

Skin: no sweat glands, cools from respiratory tract; main gland is Uropygial,

Small intestine: where most of absorption of nutrients takes place; liver and pancreas are connected to this tube through ducts

Somatosensory receptors: relating to sensory stimuli from skin; describes sensory stimuli coming from the skin and internal organs and the perception of the stimuli; the receptors receive the stimuli

Species: level of classification below “genus;” individuals share distinctive characteristics and are unlikely to breed with other such groups of individuals

Spectacle: combination of the eye ring and supraloral line

Spermatocyte: the type of gametocyte that produces sperm

Sputum: mucous secretion from lungs, trachea and bronchi

Squamous: covered with or resembling scales

Staphylococcus: bacteria associated with skin infections

Stain: pigment or dye used to color tissue for aiding identification under microscope

Stasis: In the gastrointestinal tract, a condition in which the food does not move through normally, but remains in one section, e.g., food does not pass from the stomach into the intestine.

Stenosis: narrowing or restricting of a passage, such as blood vessel or intestine

Sternum: large bone underlying the breast—keel

Stomatitis: inflammation of the mouth or other small apertures; stoma can be artificial opening between hollow organ and outside of body, e.g., pass wastes

Stratified: to form or arrange in layers, layered

Stricture: abnormal narrowing of a passage

Strongyle: parasite; nematode worm

Stupor: state of mental dullness, failure to normally respond to stimulus

Subcapsular: Beneath or below A membranous sac or integument

Subclinical: disease below clinical level; bird is ill but not showing signs; early stage of disease or mild form of it

Subcutaneous: beneath the layers of the skin

Suberous/Subserosal: situated or occurring under a serous membrane

Sulci: (pl of sulcus): sulci grooves a groove or fissure between two convolutions of the brain.

Sulfonamides: A class of antibiotics which contain sulfur. They are bacteriostatic; they stop the growth or reproduction of bacteria, but do not kill them).

Superciliary line: arch of feathers growing overtop the bony arch of each eye in the same location as the human eyebrow. Also called supercilium or eyebrow

Superior umbilicus: navel-like formation located above an organ

Suppurative/suppurate: to produce or discharge pus, as a wound; the matter produced by suppuration: pus; a medicine or application that promotes the production or discharge of pus

Supraloral line: the line above the lore; in many species it is brightly colored line between the eye and the beak

Syndactyl: two front toes partially joined, as in kingfishers

Synovia: (Synovial membrane): lubricating fluid resembling the white of an egg, secreted by certain membranes, as those of the joints
Synovitis: Inflammation of a synovial membrane

Synsacrum: last 2 vertebrae of lower back (pelvis) and first 2 tail vertebrae, joined in a unit

Syrinx: organ located at the base of the trachea, where it branches and divides to form the bronchi; used for sound production; where the trachea bifurcates into primary bronchi

Syringial Membrane: site of opportunities for bacteria and fungal infections (aspergillosis)

Systemic: refers to total body involvement; i.e., 1:200 is good immunity or antibody response; a poor titer is lower than 1:10


Titer: a measure of antibody formation (see systemic)

Tachycardia: rapid heart beat

Tachypnea: excessively rapid respiration

Tail: long feathers extending from the rear, used for balance and attracting potential mates
Tail coverts: shorted tail feathers covering the bases of the long tail feathers

Tail numbering: system assigning a number to each tail feather, can convey certain characteristics about certain species

Tarsus/tarsi: lowest segment of leg, before the toes; between the knee and the foot; like lower leg in humans

Tarsometatarsus: the bone underlying the tarsus; consists of fused bones. Elongated tarsometatarsus looks like the shin bone, so you think that the joint should bend like  a knee, but the knee is up higher, in the feathered area of the leg, and does bend the same as human’s does

Taste buds: lie at base of the tongue, in parrots the taste buds are on the roof of the oropharynx on either side of the choana, and on the floor of the oropharynx at the front end of the laryngeal mound

Taxonomy: classification of organisms in an ordered system that indicates relationships; Class, Order, Family, Genus, Species

Temporar canthus: outer corner of the eye closest to the ear

Tenesmus: difficulty passing droppings due to papillomas
Teret:(ter’eet) round in cross section/circular and smooth with a circular transverse section, cylindrical or slightly tapering

Tertials/ Tertiary feathers: flight feathers attached to upper arm (Humerous) attached to the basal joint of the wing; next to the secondaries (shorter, upper "arm" feathers)

Tibia: segment of leg that protrudes from feathers, above “ankle”; like human upper leg, above the knee and below the body

Titer: A measurement of the number of antibodies in the blood. The test to measure antibodies is usually performed by making a number of dilutions of the blood and then measuring at what dilution there is sufficient antibody to react in the test. For example, a titer of 1:8 (one to eight) means the blood can be diluted to one part blood and seven parts saline and still produce a positive reaction in the test. The higher the titer (1:16 is higher than 1:8), the more antibody is present. (NOTE: The word 'titer' may also be used when discussing the amount of antigen present, e.g., a high titer vaccine has a large number of virus particles.)

Toes: Digits 2 and 3 point forward, and digits 1 and 4 are back.

Tomia: cutting edge of both maxilla and mandible; lower mandibular tomia is the cutting edge of the mandible; Upper mandibular tomia: cutting edge of the maxilla

Torticollis: stiff neck caused by spasmodic contractions of the muscles drawing the head to one side with the chin pointing to the other side; wryneck

Tortuous: full of bends, turns, twists, winding,

Toxic: toxicity of cells; as toxic heterophil is “sick” from fighting disease, toxic refers to being poisoned; detoxification refers to removing toxin

Toxin: the poisonous causative agents of disease; plant or animal origin

Toxic heterophils: heterophils that are sick from fighting diseases; usually means a serious problem; this would be a bad sign and an example of abnormal leukocyte morphology

Trachea: windpipe

Tracheitis: infection - Inflammation caused by bacterial or viral agent

Tracheal mucosa: consists of smooth, stratified squamus epithelium

Trailing edge of the wing: edge seen when wing is stretched out in flight and viewing it from the rear end of the bird; area where the edge of the feathers is located,  the area where feathers are attached is leading edge of the wing

Transillumination: to throw a light across or through an organ as a means of diagnosis

Tremors: uncontrolled shaking

Trichomoniasis: disease of digestive tract and other organs caused by flagellated protozoan, trichomonas

Tri-Chrome: special test for Giardia and other protozoa; suspends the parasites, making them easy to find

Trocar: a sharp-pointed instrument enclosed in a cannula, used for withdrawing fluid from a cavity, as the abdominal cavity

Trunk: whole body between neck and tail; divided into thorax, abdomen and pelvis; Thorax is bounded by the rib cage, sternum (keel) and vertebral column (backbones). Abdomen and pelvis not separated by well-defined boundaries; top part of the trunk is divided into the back and the rump; the region between the right and left shoulder blades (scapulae) is called the interscapular region, and often carries distinctive streaks or colors; whole back, combined with the top surface of the wings in called the mantle; Side area of the trunk is the flank; underside is divided into the breast, belly and undertail; Crissum is the general area around the vent, along with the undertail covert feathers; vent is only the orifice, and not the general area of the tail.

Tumors: abnormal tissue growth resulting in a mass that may be benign or cancerous (malignant)
- Wing tumors: swellings or mass anywhere on wing, tumors are large masses with muscles or skin on wings,  also in bone; surgery, amputation asap

Turgidity: Turgid: swollen, distended

Turgor /turgescence: the normal rigid state of cells, caused by outward pressure of the water content of each cell on its membrane


Ulceration: open sores

Ubiquitous: found everywhere and around the world

Ulnar vein: vein by the ulna (bone in forearm opposite thumb—alula)

Ultrasound: used in larger birds to characterize lesions, wound, injury, disease

Underparts: seen looking up at a bird during flight: belly, undertail coverts (vent), chest, flanks and foreneck

Upperparts: visible when viewing from top: back, rump, hindneck, wings and crown

Undertail coverts: feathers in a triangular area on the undersurface of a bird between vent and base of tail feathers (crissum)

Underwing: bottom side of the wing; when stationary, the side pressed against the body; when in flight, the side seen when standing on the ground looking up

Upperwing: seen from top view; exposed when bird is stationary and has wings pressed against body

Unthrifity: visually appearing to be dull, listless, underweight, not picture of radiant health

Urate: A chemical compound which contains uric acid and is made by the kidney, and can form crystals and stones in the urodeum (urinary bladder.) Uric acid is a waste product from the breakdown of certain proteins; white portion of the droppings, crystalline urine

Yellow or green=liver disease
Brown, rust/red colored=heavy metal toxicity

Ureter: tube that carries urine from kidney to cloaca

Uricemia: increased uric acid in the  blood, leads to gout

Urodeum: like a bladder, holds urine till it goes into the cloaca

Urolith’iasis: stones in the urinary tract; formation or presence of stony masses in urinary tract, or the medial condition resulting from this

Uropygial gland: papilla on top of uropygium (by tail) that secretes oils for preening; oil keeps the skin supple and the feathers and scales from becoming brittle, but do not appear to waterproof the feathers; has antibacterial and anti-mycotic properties; has an odorant and/or pheromonal function, sense of smell is better developed in birds than formerly realized

Uropygium: fleshy posterior end supporting the tail


Vaccine: suspension of infectious agents, either killed or attenuated (weakened), given to establish resistance or immunity to an infectious disease

Vaccination: injection of vaccine

Vanes: rows of interlocking barbs on feather that protrude from shaft

Vascularity: vascular: vessels or ducts that convey fluids, such as blood or lymph

Vascular/vascularized: pertaining to, composed of or provided with vessels or ducts that convey fluids, as blood or lymph, rendered vascular by the formation of new blood vessels, supplied with blood vessels

Vectors: animal or organism that carries disease from one host to another; e.g., mosquito, flea, etc.

Vena cava:  Either of two large veins carrying blood to the right atrium of the heart. The cranial vena cava brings blood from the head region, front legs, and upper chest to the heart; the caudal (or posterior) vena cava carries blood from the areas of the abdomen and hind legs to the heart.

Vent: Opening of cloaca

Vent Glands: small, tubular glands on lips of vent; outside or inside, secrete only mucoproteins, enlarge during breeding season

Ventriculus: 2nd part of stomach; grinds the food for absorption in the small intestine; produces pepsin and other enzymes

Vertebrae: small bones in spine, 12 neck, 8 thoracic, 8 lumbar, 8 tail, fused at pygostyle

Viremic: virus in the blood

Virulence: competence of any infectious agent to produce disease and the degree of bodily damage it is capable of producing; highly infectious disease organism.

Virus: The smallest form of life, invisible with an ordinary microscope; an infectious unit that enters and uses cells of plants or animals for replication. Some viruses cause disease in animals or plants.

Viscera/Visceral: pertaining to any interior organ in any of the great body cavities; especially in the abdomen

Vitelline membrane: transparent membrane surrounding and holding together the yolk of an egg

Volvulus: torsion or twisting of the intestine, causing obstruction


White blood cells: Cells in the blood whose major role is to defend the body against invading organisms such as bacteria, viruses, and fungi. There are different types of leukocytes: lymphocytes are part of the immune system; monocytes, eosinophils, and neutrophils eat or engulf organisms; basophiles contain histamine and are involved in inflammatory reactions.

White Blood count: total number of white cells per low-power field; measure of normal vs. disease state

Wing bars: make the bird’s wing look “striped, pale or white tips of greater and median secondary coverts; view as a horizontally striped pattern making wing look layered

Wing lining: shorter and softer median, lesser and marginal coverts on the underwing

Wrist: base of the primaries (longest wing feathers) in the wing, not as flexible as human wrist


Xanthomas: benign tumor made of fatty cells and cholesterol; often associated with hypothyroidism, Clostridium, subclinical and clinical illness, result of high-fat seed diet, poor immune system


Yolk: yellow portion containing all the lipids (fat) and most of the protein needed by developing embryo; surrounded and held together by the transparent vitelline membrane


Zoonotic (zoonosis): A disease which can be transmitted between animals and people

Zygodactyl: two toes in front and two behind; 2 and 3 face forward, 1 and 4  face backward

Zygomatic Arch: bony arch at the outer border of the eye socket, formed by union of cheek bone and temporal bone

Other Article Contributions by Jeannine Miesle

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