POLYOMA (Part 2) — Budgerigars

1. Why is Polyoma different in budgies than in other parrot species?

Polyomavirus in budgies is the same virus as seen in other species. However the signs and course of the disease are more complicated than in other parrots as the virus may be present for several years. In other parrot species the virus is not usually present for more than a few months.

2. How is the virus transmitted from budgie to budgie?

Transmission is via the eating or breathing-in of infected droppings, skin and/or feather dust.

Budgies, unlike other birds, shed viral particles for up to 6 months after infection. They may carry the virus for up to 4-5 years.

3. What are the clinical signs of Polyoma in the acute form?

Death in birds aged 10-25 days. The dead birds have skin discolouration, abdominal distension, ascites (fluid in abdomen) and a swollen liver.

If the virus attacks the cerebellum (a portion of the brain) the birds will display head tremors.

4. What are the signs of long-term Polyoma?

Budgies that survive may show no outward signs and may develop normally but often still shed viral particles.

Many survivors will fail to develop their primary and secondary wing and/or tail feathers. These birds are called "runners" and the disease is often called "French Moult". The signs are similar to Psittacine Beak and Feather Disease (PBFD). PBFD and Polyomavirus can occur concurrently.

5. How is Polyomavirus identified in the live bird?

Most avian veterinarians cannot definitely identify the disease on clinical signs alone though the age of the birds’ deaths and the survivors’ feather signs may be suggestive of Polyoma.

A PCR (Polymerase Chain Reaction) test on blood, feathers and faeces has also recently become available. Birds can be tested up until 6 months after infection.

6. What method of control is available for budgie aviaries infected with Polyoma?

First, stop the birds breeding. Birds less than 6-12 months of age should be removed from the aviary and not returned. Older birds should be moved to a clean environment in order to allow the breeding aviary to be thoroughly disinfected. On returning these older birds to the aviary breeding should not be recommenced for at least 1 season (6-12 months).