POLYOMA (Part 1)
1. What is Polyoma?
Polyoma is a disease caused by a very small stable virus called a Polyomavirus. The virus is associated with feather changes in young birds. It is also associated with immunosuppression and can affect multiple organs in the body including the brain, liver, kidney, spleen and heart.
2. How is the virus transmitted from bird to bird?
Transmission is by the eating or breathing in of the infected bird's droppings or feather dust. Parents may pass it to chicks during feeding. Transmission may also occur in the uterus to the egg.
3. What are the clinical signs of Polyoma in the acute form?
Vomiting, regurgitation and death within 1-2 weeks may be seen. Feather changes are uncommon. Often bruising of the skin is seen and severe life-threatening bleeding episodes after intramuscular injections may occur.
4. What are the signs of long-term Polyoma?
Feather discolouration and deformities similar to Psittacine Beak and Feather Disease. Delayed crop emptying, skin bruising, tremors and weakness may be seen. Secondary infections to common illnesses are often seen in these immunodeficient birds. Many birds show few signs.
5. In which bird species is Polyoma seen?
It is seen in all parrot species. The disease’s most noticeable signs are in budgerigars. It most commonly affects young birds between 4 – 16 weeks of age but can affect birds of any age especially in eclectus, lovebirds and budgies.
6. How is Polyomavirus identified in the live bird?
Most cases of Polyoma cannot be definitely identified by clinical signs alone.
A biopsy of the feathers and the feather follicles may identify viral particles. A PCR (Polymerase Chain Reaction) test on blood, feathers and faeces has recently become available.
7. What is the treatment for Polyoma?
There is no specific treatment for Polyoma. The secondary infections need to be treated and a non-stressful environment combined with a balanced diet may help during the course of the disease. Vaccines are at present being trialled in North America but are not yet available in Australia.
8. Will any birds fully recover?
In birds under 16 weeks of age with no natural immunity to the virus the disease may be fatal. Older birds that produce an antibody response often recover and/or become carriers of the virus. Some possible carriers include budgies and lovebirds.