Continued from page 4How widespread is polyomavirus in companion birds?
As mentioned above, budgerigars are considered to be the reservoir for polyomavirus and any area in which budgerigars are housed should be considered contaminated with polyomavirus. The reported seroprevalence of polyomavirus in non-budgerigars varies from 10% to 63% depending on the flock. Considering all the data in the literature, the average seroprevalence rate of polyomavirus in non-budgerigars is about 30%.
By comparison, the seroprevalence of parvovirus in dogs in 1984 was about 50%, there were less than 600 cases of rabies reported in domestic animals in 1987 (there are about 100 million dogs and cats in the United States), and HIV is thought to infect 1 in 1000 (0.1%) people in the United States. Thus, polyomavirus activity is at least as common as parvovirus in dogs, less common than rabies activity in dogs and cats and less common than HIV infections in people residing in the United States. In a study of necropsy submissions designed to determine the most common problems in psittacine birds, polyomavirus was found to be a leading cause of death in psittacine birds.22
Is an aviculturist more likely to have problems with polyomavirus if they overbreed their birds?
In non-budgerigar psittacine birds, continued or excessive breeding would be expected to place increased stress and nutritional demands on a hen. Any stress or malnutrition might decrease the natural resistance of a bird to any infectious disease. However, as discussed above, polyomavirus is capable of infecting a "healthy" bird suggesting that any stresses associated with breeding would be of minimal importance in the epizootiology of the virus within a breeding population. For the general health of your birds, it is best to prevent overcrowding, maintain excellent air quality (no cigarette smoke, no disinfectant fumes, plenty of fresh air) and provide a high quality formulated diet.
Is a polyomavirus infection the result of a "broken down" weakened immune system?
Polyomavirus is capable of infecting a "healthy" bird, just as parvovirus is capable of infecting a "healthy" dog and HIV is capable of infecting a "healthy" person. In a broad simplified manner, the immune system can be considered responsible for protecting an animal from all infectious agents. Excepting this generalized view of the immune system, all disease involves a failure of the immune system to properly do its job. Vaccines are used widely in humans, dogs, cats, horses, cattle, chickens etc, to help the immune system protect the body from infectious diseases.
Acknowledgments
Major sustained contributions that have made this work possible have been provided by the Cowan Avian Health Foundation, the International Avian Research Foundation, Veterinary Medical Experiment Station, Joe and Sue Still, Terry Clyne, Richard and Luanne Porter, Knick Enterprises, Bobbi Brinker, Kathleen Szabo, International Aviculturist's Society, Midwest Avian Research Exposition, National Aviary, Puerto Rican DNR, Ann Arbor Cage Bird Club, Aviary and Cage Bird Club of South Florida, Avicultural Society of Puget Sound, Central Indiana Cage Bird Club, Charlotte Metrolina Cage Bird Society, Cream City Feathered Friends, Dallas Cage Bird Society, Feathered Friends Society, Gateway Parrot Club, Georgia Cage Bird Society, Greater Brandon Avian Society, Hookbill Hobbyists of Southern California, Kentuckiana Bird Society, Kenosha Exotic Bird Club, Louisiana Aviculture Society, Northwest Ohio Exotic Bird Club, South Jersey Bird Club, Wasatch Avian Education Society, West Valley Bird Society and Zeigler Brothers Inc. Hundreds of aviculturists, bird clubs and veterinarians have also made significant contributions.
References
1. Clubb SL, Davis RB. Outbreak of papova-like viral infection in a psittacine nursery-a retrospective view. Proc Assoc Avian Vet. 1984, pp 121-129.
2. Jacobson ER, Hines SA, Quesenberry K, et al. Epornitic of papova-like virus-associated disease in a psittacine nursery. J Am Vet Med Assoc 1984; 185:1337-1341.
3. Graham DL, Calnek BW. Papovavirus infection in hand-fed parrots: Virus isolation and pathology. Avian Dis 1987; 31:398-410.
4. Stoll R, Luo D, Kouwenhoven B, et al. Molecular and biological characteristics of avian polyomaviruses: isolates from different species of birds indicate that avian polyomaviruses form a distinct subgenus within the polyomavirus genus. J Gen Virol 1993; 74:229-237.
5. Speer BL. The eclectus parrot, medicine and avicultural aspects. Proc Assoc Avian Vet. 1989, pp 239-247.
6. Schmidt RE, Goodman GJ, Higgins RJ, et al. Morphologic identification of papovavirus in a Moluccan cockatoo (Cacatua moluceensis) with neurologic signs. Assoc Avian Vet Today 1987; 1:107-108.
7. Ritchie BW, Niagro FD, Latimer KS, et al. Polyomavirus infections in adult psittacine birds. J Assoc Avian Vet 1991; 5:202-206.
8. Pass DA, Prus SE, Riddell C. A papova-like virus infection of splendid parakeets (Neophema splendida). Avian Dis 1987; 31:680-684.
9. Pass DA. A papova-like virus infection of lovebirds (Agapornis sp.). Aust Vet J 1985; 82:318-319.
10. Enders F, Gravendyck M, Gerlach H, et al. Fatal avian polyomavirus infection during quarantine in adult wild-caught red-faced lovebirds (Agapornis pullaria). Avian Dis 1997;41:496-498.
11. Graham DL. An update on selected pet bird virus infections. Proc Assoc Avian Vet. 1984, pp 267-280.
12. Ritchie BW. Avian Viruses: Function and Control.Lake Worth, FL: Wingers Publishing, 1995.
13. Wainwright PO, Lukert PD, Davis RB, et al. Serological evaluation of some psittaciformes for budgerigar fledgling disease virus. Avian Dis 1987; 31:673-676.
14. Niagro FD, Ritchie BW, Lukert PD, et al. Avian polyomavirus. Discordance between neutralizing antibody titers and viral shedding in an aviary. Proc Assoc Avian Vet. 1991, pp 22-26.
15. Niagro FD, Ritchie BW, Latimer KS, et al. Use of polymerase chain reaction for detection of PBFD and BFD in suspect birds. Proc Assoc Avian Vet. 1990, pp 25-37.
16. Ritchie BW, Vaughn SB, Rich GA, et al. Control of polyomavirus epornitics through vaccination. Submitted for publication, 1997.
17. Ritchie BW, Pritchard N, Pesti D, et al. Susceptibility of avian polyomavirus to inactivation. J Assoc Avian Vet 1993; 7:193-195.
18. Phalen DN, Wilson VG, Graham DL. Organ distribution of avian polyomavirus DNA and virus-neutralizing antibody titers in healthy adult budgerigars. Am J Vet Res 1993; 54:2040-2047.
19. Ritchie BW, Latimer KS, Pesti D, et al. Vaccination to control polyomavirus in budgerigars. Proc Assoc Avian Vet 1997; In press.
20. Tabachnick WJ, MacLachlan NJ, Thompson LH, et al. Susceptibility of Culicoides variipennis sonorensis to infection by polyomerase chain reaction-detectable bluetongue virus in cattle blood. Am J Trop Med Hyg 1996; 54:481-485.
21. Bergmann IE, Malirat V, Auge de Mello P, et al. Detection of foot-and-mouth disease viral sequences in various fluids and tissues during persistence of the virus in cattle. Am J Vet Res 1996; 57:134-137.
22. Schmidt RE: Geographic pathology of pet avian diseases. Proc Assoc Avian Vet, 1997; In press.
| Top | Back |
 NetPets® Main Page |  The Bird Center |