We are often asked about vaccinating our parrots. And the answer is, well, maybe. We have limited vaccines and some have come and gone from the market — mostly gone. The only vaccine available is the polyomavirus vaccine. So what should we do?
Polyomavirus at one time was killing our parrots — mostly hand-reared chicks and sometimes adults, and often in large numbers. In budgies, the disease would affect the nestlings from 10-25 days of age, causing death acutely. Larger parrots are also susceptible to avian polyomavirus (APV) infection but usually do not have signs of disease. Some species are highly susceptible to disease, especially caiques, while others rarely if ever develop signs of disease.
APV-disease occurs at different ages in different species. In conures, death typically occurs in birds less than 6 weeks of age. Death in macaws and Eclectus parrots occur at about (8 weeks) weeks or younger. Most, possibly all, of the nestlings lost are being hand-fed when this happens. Infected chicks that are being hand-fed appear healthy, show very few premonitory signs, and then die suddenly. Chicks kept in the nest box, being fed by the parents, rarely develop disease; this fortunate outcome is due to the transfer of secretory antibody. When signs do occur, they precede death by up to 24 hours. Observant owners may notice delayed crop emptying, weakness, a generalized pallor, or bruising under the skin in the preceding hours before death. Yellow discoloration of the urates is another rare observation. Necropsy findings typically include generalized pallor with subcutaneous and subserosal hemorrhages and enlargement of the spleen and liver. Less commonly, ascites of abdominal fluid and/or pericardial effusion around the heart may be present.