Psittacine Beak and Feather Disease
Believed to have originated in Australia, Psittacine Beak and Feather Disease (PBFD) is now spreading around the world. The condition is afflicting both pet birds and wild birds and is caused by a Circovirus which evolves quickly, spreads easily and can survive for many years in nests.
African grey and Eclectus parrots, macaws, cockatoos, love birds and ring-necked parakeets appear to be particularly susceptible to PBFD. However, more than 60 species have been found to be infected with the disease.
The birds which have fallen prey to PBFD have included several populations of endangered species including the orange bellied and Norfolk Island green parrots. The disease was first identified in 1987 and for a time seemed confined to Australia but was then discovered to have reached New Zealand. There, it has sadly been responsible for killing rare yellow-crowned parakeets. PBFB is now spreading across the world.
Symptoms and Treatment
The disease has been researched but thus far no cure has been found. PBFD manifests itself in three different forms. Peracute and Acute PBFD afflict hatchlings and nestlings, and quickly lead to death. Infected birds become lethargic, and may vomit and can exhibit abnormal feather growth.
Adult parrots which become infected with chronic PBFD can be helped a little by strengthening their immune system, but they generally succumb to the disease eventually. The afflicted birds may exhibit feather abnormalities such as the loss of powder down, curled feathers, retained sheaths and colour changes. Their beaks, especially those of cockatoos, may flake and crack, and nails may curl as they grow. Diarrhoea, lethargy and vomiting are further symptoms which are often seen. The presence of the disease can be confirmed by a blood test.
PBFD suppresses the immune systems of the birds and so death is often the result of a secondary infection.
It has been found that a good diet, exposure to sunlight or a UVA/UVB lamp and a natural day/night cycle can be useful.
PBFB may incubate in a bird for 3 weeks to 12 months, during which time symptoms will not be evident. Birds incubating the virus will, however, shed it in the faeces and feather dust and so will spread the infection. In rare cases, adult parrots have been known to survive PBFD. Unfortunately, they continue to shed the virus throughout their lives.
PBFD is now considered to be a serious threat to the survival of several rare species in Australia and New Zealand. Australia’s Environmental Protection and Biodiversity Act provides for a PBFD management program. Meanwhile, the search for an effective vaccine continues. Captive birds can be managed but rarely cured and euthanasia is often necessary.
How Did the Virus Spread?
Escaped and released non-native parrots, products of both the legal and illegal pet trades, were believed to be the cause of the PBFD outbreak in New Zealand. Eastern Rosellas, which are native to Australia but feral in New Zealand, were discovered infected with the virus. The situation is likely to get worse before it gets better.