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PSITTACINE
BEAK AND FEATHER DISEASE
Causative
Agent
This
disease was formerly believed to be caused by a Parvovirus based on its
appearance under the electron microscope. Recently, the causative virus has been
shown to be a virus previously uncharacterized in the veterinary literature. It
has been purified and characterized as a double stranded DNA virus of 15 - 17
nanometers diameter. Finally, the important step of fulfilling Koch's postulate
has been completed in that the virus has been isolated, characterized,
re-introduced to healthy birds, physical symptoms of the disease noted, and the
virus has been recovered from those birds. This virus has been repeatedly
isolated from symptomatic as well as asymptomatic Cockatoos, suggesting that the
presence of this virus in these species is common, even though the disease is
not shown to be physically or histopathologically evident.
Susceptible
Species
Virtually
all of the African and Australian and Indonesian origin Psittacine birds should
be regarded as having a relatively high susceptibility to this infectious viral
disease. Viral infection with this agent is particularly uncommon in South
American parrot species
Symptoms
Fledgling
or immature birds are commonly noted with any one or a combination of the
following symptoms:
-
Abnormal
moult with diseased blood feather regrowth.
-
Depression
and weakness.
-
Weight
loss and reluctance to wean.
-
Death.
Adults with Beak and Feather Disease will frequently show one or more of
the classic symptoms:
-
Progressive
loss in the amount of powder and feather dust. This observation may
frequently lead to the comment that the beaks are black and shiny due to the
absence of the normal amount of dust.
-
Abnormal
moult with diseased feather regrowth.
-
Abnormally
rapid and progressive growth of the upper and lower mandibles of the beak.
-
Necrosis
and "rotting" of the beak. This is frequently inside of the upper
mandible along the palatine surface, however it may occur anywhere on the
beak. The necrosis and "rotting" of the beak is frequently
associated with pain and secondary infection.
Clinically,
Lovebirds and Eclectus species rarely show beak involvement and usually die
suddenly with a relatively short course of the disease. Young African species (Greys,
Poicephalids, Lovebirds) may show a progressive anemia and white blood cell
count drop as a unique manfestation of PBFD virus infection.
Diagnosis
Presumptive
- Symptoms in the most susceptible species.
(Old
world parrot species)
Definitive
- Physical examination by a qualified Avian Veterinarian.
Skin
and feather pulp biopsy (multiple biopsies may be required).
DNA probe (PCR) testing is available, and can be performed on whole blood
samples as well as fixed biopsy specimens. These DNA tests should be performed
by your avian veterinarian through a recognized and reliable laboratory.
Treatment
There is no proven treatment for this disease.
With supportive care, some effected birds with the chronic form of
disease can live for years.
Probable
Routes Of Transmission
The manner of transmission of this viral disease is known to be via shedding in
the feces and feather dust and dander. Experimentally, it has been shown that
the disease can be reproduced by intra-cloacal as well as oral inoculation with
purified virus.
Control
Aviary
Australian
breeders feel that the incidence of disease can be reduced by strict nest box
sanitation. Some feel that the disease is in greater incidence when a nest box
has not been cleaned between several successive clutches. Dampen down the
flights with a dilute disinfectant solution, scrub, and clean away all organic
material. Re-treat with dilute disinfectant and allow to air dry. If organic
material cannot be completely cleaned or removed, the types of disinfectants to
be used should be adjusted carefully with the assistance of your avicultural
Veterinarian. Of course, all clinically affected birds should be removed from
the premises.
Nursery
Keep
individual clutches separate, and disinfect your hands and feeding materials
between the groups of babies. As mentioned previously, consult with your
avicultural Veterinarian as to which disinfectant is appropriate for your
specific situation. Realize that the spread of this disease in the nursery is
usually associated with concurrent exposure to other pathogens. Hence,
elimination of any other existing bacterial or Chlamydial organisms, which may
be causing a low-grade immunosuppression, is important. Since many antibiotics
are immunosuppressive, avoid their use unless absolutely necessary and only
after consulting with a qualified avian Veterinarian. Increased incidence has
been reported in nurseries, which have had concurrent Papovavirus, Reovirus,
Salmonella, and Chlamydial problems.
Disinfectants
Bleach
at one cup per gallon or Wavicide are our recommended products for use in
disinfecting against this virus. Consult with your veterinarian regarding proper
usage and be sure to complete this use with complete closed aviary protocol as
well.
Comments
This disease is not rare, and carries a devastating impact to
the aviculturalist, the commercial shop, and most importantly the pet bird owner
whenever diagnosed. Most Cockatoos with this disease do not die rapidly; hence,
their owners are forced to helplessly watch their family member slowly progress
with this horrible debilitating disease. Because of the usual strong human
- bird bond that develops between pet Cockatoos and their owners, the emotional
impact of this disease is immense. Unfortunately, when the pet birds' quality of
life becomes poor in the later stages of disease, these owners are frequently
forced make the decision to have the birds euthanized, since they will not die a
rapid and pain free death at home. Threats of litigation are common due to the
tremendous emotional and financial devastation that can be generated, and avian
Veterinarians, bird breeders, and pet retailers should consider themselves at
risk.
We, as aviculturalists,
commercial pet stores, and Veterinarians must support continuing research into
this disease whenever possible. Please do not hesitate to ask how you can become
involved in the efforts to bring this killer under control.
Information
Provided by:
Brian
L.
Speer
,
DVM, DIP, ABVP, ECAMS
Certified
in Avian Practice
European-Certified
Avian Specialist
The
Medical
Center
For Birds
3807
Main Street
Oakley
,
CA
94561
Phone:
925-625-1878
Fax:
925-625-8511
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