Bacterial and Viral Diseases
Bird Health Care
Fungal Infections by Dr. Rob Marshall ... Microbiology for the Aviculturist: Do your own cultures or gram stains - step-by-step instructions
Vinegar: A Natural Approach to Avian Management
Chicken Pox / Fowl Pox ... Coryza ... Epidemic Tremor ... Fowl Cholera ... Infectious Bronchitis ...
Lymphoid Leucosis ... Marek's Disease ... Avian Influenza
(For more in-depth information on each of the above diseases, please
go to the Bird Disease page)
CHICKEN POX OR FOWL POX (SOREHEAD)
Cause: A virus.
Transmission: Mosquitoes are considered an important means of transmission.
Lesions: Wart-like nodules covered with brown scabs on the
bare parts of the head, feet and around the vent. Yellowish cheese-like
areas may occur on the inside of the mouth.
Treatment: None.
Control: All birds intended for laying purposes should be
vaccinated. Birds whose resistance has been weakened through any
condition or disease should not be vaccinated until they are healthy.
CORYZA
Cause: Simple coryza, the common cold, is usually caused by improper management
in which birds are subjected to undue exposure. Infectious coryza
is caused by a specific microorganism and its severity is increased
in birds subjected to resistance lowering factors.
Symptoms: Respiratory distress accompanied by watery and
swollen eyes and unthrifty condition.
Treatment: Simple coryza responds to correction of undue
exposure. Antibiotics are beneficial. Infectious coryza sometimes
responds to erthyromycin, streptomycin and sulfonamides if treated
early.
Control: Depopulation of farms and starting with clean chicks.
Consider vaccination if exposure risk is high.
EPIDEMIC TREMOR
Cause: A virus.
Symptoms: A disease affecting chickens clinically under 6
weeks of age. Incoordination of gait, staggering, falling to one
side, occasional tremors of the head. Excitement intensifies symptoms.
Treatment and Control: No treatment except isolation of affected
birds. Vaccinate breeder flocks to provide immunity to chicks.
FOWL CHOLERA
Cause: A bacterial organism, Pasteurella Multocida.
Symptoms: Sudden death, greenish diarrhea, high temperature,
comb and wattle purple. Also swollen wattle. A chronic form of the
disease exists in which lesions localize in a joint, wattle, infraohits
(Author Note), sinuses or other tissue.
Treatment: Many drugs are available.
Control: Improve sanitation. Depopulate and use one age birds
on farms. Bacterins may be used to aid prevention.
INFECTIOUS BRONCHITIS
Cause: A virus.
Symptoms: Respiratory distress, sneezing and rattling. In
laying birds, a drop in egg production, misshaped eggs with low
quality. Some strains of the virus may cause severe kidney damage.
Treatment: None.
Control: Vaccination.
LYMPHOID LEUCOSIS
Cause: A virus of the leukosis-sarcoma complex.
Occurs mainly in laying hens between 4 and 10 months or age.
Symptoms: Tumors in the bursa of Fabricius will spread to
many other internal organs, especially the liver, spleen and kidney.
Treatment: None.
Control: Development of resistant strains of chickens by Poultry geneticists.
MAREK'S DISEASE
Cause: A herpes-virus. Occurs mainly in chickens under 16 weeks of age.
Symptoms: Leg and/or wing paralysis, high mortality, tumors on visceral organs.
Treatment: None.
Control: Vaccination of chicks at one day of age.
NEWCASTLE DISEASE
Cause: A virus.
Symptoms: Respiratory distress, and rasping followed in 1 or 2 days by a paralysis of
legs and wings and bad down between legs or straight back over shoulders,
twisting of neck (stargazing). In adult birds, loss of production along with some
respiratory distress and paralysis after 4 to 6 days.
Treatment: None.
Control: Vaccination.
AVIAN INFLUENZA
Cause: A virus. Highly infectious, severity varies.
Symptoms: Sudden death is common. Clinical signs include sudden
drop in egg production. depression, loss of appetite, blue combs
and wattles, diarrhea, blood-tinged discharge from nostrils.
Treatment: None.
Control: Monitoring, strict quarantine and rapid destruction
of all infected flocks. Poultry producers should practice strict management control.
* From Diseases of Poultry, a paper by Dr. Gary D. Butcher,
DVM, PhD., Poultry Veterinarian, College of Veterinary Medicine,
Institute of Food and Agricultural Sciences, University of Florida,
Gainesville. From publication PS-5, Florida Cooperative Extension Service.
If you would like to add to or correct any of the above information, or would like to share with web visitors your own experiences, please e-mail the webmaster.
Photo contributions are welcome!
