Trichomonas gallinae in budgerigars and columbid birds in Perth, Western Australia.

OBJECTIVE: To estimate the prevalence of infection with Trichomonas gallinae and other parasites of the alimentary tract in psittacine and columbid birds in Perth and to determine in vitro the effectiveness of drugs commonly recommended for treating trichomoniasis. DESIGN AND PROCEDURES: Samples of crop contents were collected from aviary flocks of budgerigars (Melopsittacus undulatus) and other psittacine and columbid birds in both private and commercial collections in Perth. Similar samples from wild Senegal doves (Streptopelia senegalensis) also were collected. Crop contents were examined and cultured for Trichomonas gallinae and in vitro studies were conducted on the susceptibility of isolates to several drugs used commonly. Other parasites also were detected by faecal examination and/or necropsy.
RESULTS: T gallinae was recovered from birds in 1 of 13 private collections of budgerigars (2/289 birds in total). Direct wet-mount examination of crop fluid identified 36.4% of samples at four commercial bird dealers which were later determined by culture to contain T gallinae. The prevalence of T gallinae infection range from 0 to 11.4% in budgerigars. The prevalence of T gallinae infection of wild Senegal doves was 46% and from one flock of racing pigeons was 59%. The in vitro minimum lethal concentrations of metronidazole, dimetridazole and ronidazole ranged from 40 to 96, 30 to 80 and 40 to 92 micrograms/mL respectively for six isolates of T gallinae. Other alimentary parasites detected during the survey included Spironucleus sp (syn. Hexamita sp), coccidia, Ascaridia platycerci and Raillietina sp.
CONCLUSIONS: Thirteen budgerigar flocks belonging to members of avicultural societies in Perth had a low prevalence of trichomoniasis and other parasitic infections. The dose rate currently recommended for ronidazole may not result in complete protozoacidal activity against T gallinae infection.