Psittacine Beak and Feather Disease, PBFD, Beak & Feather
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PBFD is caused by a virus which infects and kills the cells of the feather and beak. The virus also impairs the immune system. Consequently many diseased birds succumb to bacterial and other infections. Psittacine Beak and Feather Disease (PBFD) is a devastating viral disease that has first been noticed in cockatoos, but has since been diagnosed in many species of birds, specifically in African Greys, budgies, cockatoos, Eclectus parrots, lovebirds, macaws, and Rosellas.
Symptoms / Disease Progression
PBFD should be considered in any psittacine bird that displays progressive feather loss or abnormal feathers. Most birds which succumb to PBFD are less than 2 years of age. However, all age groups should be considered susceptible to circovirus infection.
Young birds are affected by an acute form of PBFD, which occurs during their first feather formation, after replacement of down feathers. The developing feathers often fracture, bleed or fall out. Young birds may die following a short period of anorexia (loss of appetite), depression and diarrhea, with very little feather abnormality.
Older birds are thought to develop a chronic form in which dystrophic feathers stop growing shortly after emerging from the follicles. The feathers become increasingly abnormal with each successive molt. Contour feathers are usually affected early, while primary feathers are affected later in the disease. Contour feathers often are lost over most of the body. New feathers may have retained feather sheaths, blood within the shafts, are curled and deformed, or are short and clubbed.
The beak may also be involved in the disease process. It may change from a dull black to a glossy appearance. It may grow abnormally long and develop splits and cracks which break and peel. Bacteria and fungi often invade the abnormal beak, causing further destruction and necrosis (death) of the tissues. The abnormal beaks often make it difficult for the bird to eat as it may be very painful.
Spontaneous recovery from acute PBFD can occur in many species. However, the majority of chronically affected birds do not recover from the disease.
Transmission:
PBFD is spread by inhalation or ingestion of virus particles. Feather dust has been found to contain a large amount of virus. The virus has also been found in crop secretions and in fecal material. The virus may also be ingested as a result of preening. The incubation period of variable among species and the age at which the bird is exposed. Again, neonates and young birds are most susceptible, while adult birds over two years of age are thought to be at less risk.
It is possible for a bird to undergo a transient subclinical infection. This means that the bird's immune system is able to eliminate the virus. This is why it is recommended that a normal appearing bird who tests positive be retested 90 days later. If the bird has eliminated the virus it will test negative. If it remains positive, it should be considered latently infected and should be expected to break out with clinical disease in the future.
This is considered a fatal disease, and there is no cure, or treatment known.
A pet bird with PBFD can live a long life, if it is in a stress-free environment. It would never have contact with other birds since it is capable of spreading the virus.
Diagnosis / Testing:
Whole, anticoagulated blood should be submitted from a bird without feather abnormalities, while both blood and several abnormal feathers should be submitted from a clinically abnormal bird. A test was developed by Dr. Brandon Ritchie, and is run by Avian Research Associates Laboratory.
Interpreting the Results of the Psittacine Beak and Feather DNA probe test.-
A. If Bird Has Dystrophic, Necrotic Feathers and you Test Blood for PBFD Virus using DNA probes:*
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1. If Positive: Suggests Active Infection
Management: : If bird is from a breeding aviary: Bird should be removed and all areas that could be contaminated with feather dust from the infected bird should be repeatedly cleaned. If companion bird: Bird should not be exposed to other birds outside of the household and you should be aware that the virus can be transported to other locations on your clothes or in your hair. Be courteous of other birds and do not expose them. It should be noted that, occasionally, some PBFD infected Psittaciformes of South American descent have spontaneously recovered from the disease.
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2. If Negative: A feather biopsy (including the feather follicle) should be submitted for histopathologic examination.
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1. If Positive: Suggests Active Infection
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B. If Bird's Feathers are Normal and you Test Blood for PBFD Virus using DNA probes:*
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1. If Positive: Indicates that the bird has been exposed to PBFD virus and that the virus is present in the blood. The bird must be retested in 90 days. If the bird is negative when retested, it indicates that the virus was not detected in the blood cells. If the bird is still positive, it indicates that the bird is either clinically infected or that the bird is being repeatedly exposed to the virus. It should be noted that most birds that are exposed to the PBFD virus develop a transient viremia followed by an appropriate immune response that results in the bird clearing the infection.
- 2. If Negative: Indicates that PBFD virus was not detected in the blood.
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1. If Positive: Indicates that the bird has been exposed to PBFD virus and that the virus is present in the blood. The bird must be retested in 90 days. If the bird is negative when retested, it indicates that the virus was not detected in the blood cells. If the bird is still positive, it indicates that the bird is either clinically infected or that the bird is being repeatedly exposed to the virus. It should be noted that most birds that are exposed to the PBFD virus develop a transient viremia followed by an appropriate immune response that results in the bird clearing the infection.
INFECTIOUS DISEASES LABORATORY DEPARTMENT OF MEDICAL MICROBIOLOGY COLLEGE OF VETERINARY MEDICINE UNIVERSITY OF GEORGIA ATHENS, GA 30602-7386
Please print and fill out this form (pdf) and fax to:706-542-5233 For questions, please call: 706-542-5812
** Please feel free to duplicate and distribute.
Branson W. Ritchie, D.V.M., Ph.D.
College of Veterinary Medicine
Small Animal Dept.
Athens, GA 30602
References / Relevant Websites : Ask the Vet - Part I: Psittacine Beak and Feather Disease) ... Ask the Vet - Part II: Psittacine Beak and Feather Disease ... Psittacine Beak and Feather Disease (PBFD) - Avian Biotech ... Current Concepts on Psittacine Beak and Feather Disease and Avian Polyomavirus ... Psittacine Beak and Feather Disease Diagnostic Flowchart ... Psittacine Beak and Feather Disease Research ... Psittacine Beak and Feather Disease - Dr S.R. Raidal BVSc PhD MACVSc; Murdoch U.
Natural Antibiotics / Strengthening Your Immunesystem Naturally
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