The avian vets, including Aidan Raftery, at the Avian and Exotic Animal Clinic have written this blog about Psittacine Beak and Feather Disease. Thank you so much to them. Read this blog to learn more about PBFD, what causes it and how to treat it.
What is Psittacine Beak and Feather Disease?
Psittacine Beak and Feather Disease (PBFD) is a common disease of Parrots caused by a very small virus called Circovirus. Symptoms vary widely depending on the species of Parrot and the age of the bird.
The name of the disease comes from the symptoms seen in the most recognisable form of the disease, i.e. changes to the feathers and beak.
Which Species are Susceptible?
African, Australian and Asian species are much more susceptible than American Parrot species. It is not common in Macaws and has only occasionally been reported in Amazons.
What are the Symptoms?
Some species such as Budgies, Lovebirds and Parakeets can be infected and shedding for a long time before showing any symptoms, or may never show symptoms.
All species become immunosuppressed usually eventually leading to death by other infections taking advantage of the reduced immunity.
Cockatoos show classical symptoms with necrosis and distortion of the beak and the growth of deformed feathers that break easily.
The necrosis of the beak is caused by PBFD. The disease has more chronic course in Cockatoos.
In African Grey Parrots the disease is mainly seen in juveniles. The symptoms are often vague, they will be lethargic, fluffed up, not eating and some have lameness of one leg.
Examination of a stained blood smear reveals a massive reduction in white cells and juvenile red blood cells. This test takes less than 30 minutes and almost confirms the diagnosis.
Poicephalus species (Meyer’s, Jardine’s, Senegal etc) and Lories often only lose primary flight and tail feathers.
Grass Parrots and other Neophema species and also Budgies develop scruffy plumage, losing feathers easily when handled.
Burkes Parakeet with typical signs seen in this species.
How is PBFD Spread?
This disease occurs in the wild in Australia and has spread all over the world where Parrots are kept. Feather dust from affected or carrier birds carry the virus. It is very resistant to all available disinfectants (in spite of several manufacturers claims) and must be removed by removing the dust, cleaning and damp dusting all surfaces. Air Purifiers can also help.
How do we Determine if My Parrot has PBFD?
PCR tests are the best and most common way to detect the virus in a bird. PCR tests show positive if they find DNA from the virus. Blood is the best tissue to sample. Some older PCR tests do not detect all strains of the virus so choice of test is important. There also is a test to detect antibodies to the virus but this is rarely used.
Histology can also be used to diagnose this condition. This can be used to confirm that the bird was not just a carrier and also to identify other infections that took advantage of the immunosuppression caused by the PBFD virus.
Fungal infection in a young African Grey Parrot secondary to PBFD. Secondary infections like this are common in Parrots infected with PBFD due the immunosuppression it causes.
What is the treatment?
Unfortunately, there is no effective treatment once the bird has clinical symptoms. Many experimental treatments have been tried but none have been successful. Individual variation in the course of the disease and the fact that some birds become infected but do not develop the disease explains the occasional anecdotal reports of successful treatment.
Birds with the feather and beak form have a long disease course. Controlling secondary infections and providing supportive care such as a good diet and minimal stress are all that can be done.
What is the best way to prevent PBFD?
Keep Parrot species that are known to frequently be carriers separate from the more susceptible species is very important. The infective part the powder down floats in the air easily infection Parrots nearby. It can also be transmitted on cloths or towels used to handle the birds. Minimising dust in the air by husbandry changes and the use of air purifiers have been proven to reduce the incidence of many infections. There is currently no vaccine available although there are several groups working on this.
If you have a collection of Parrots or breed Parrots then you should discuss with your avian veterinary surgeon the controls you should put in place to prevent this infection getting onto your birds.
Dr Aidan Raftery MVB CertZooMed CBiol MRSB MRCVS
Dr Lianne Foxall-BVSC,MRCVS and Dr Filipe Martinho DVM MRCVS
Avian and Exotic Animal Clinic
@Ashleigh Veterinary Centre
221 Upper Chorlton Road
0161 881 6868
Find out more about them in their blog here