Two morphologically distinct trypanosomes (Trypanosoma ontarioensis n.sp. and Trypanosoma paddae) were found by the haematocrit centrifuge technique in the blood of 53% (64 of 121) of Corvus brachyrhynchos brachyrhynchos wintering in southern Ontario. Trypanosoma ontarioensis n.sp. is a small trypanosome with subterminal kinetoplast. It is monomorphic and not host specific. It was readily cultured in diphasic blood-agar medium. Two-week cultures were infective and contained dividing sphaeromastigotes, epimastigotes, and trypomastigotes. Blood trypomastigotes were detected in low numbers in the blood of inoculated birds (Corvus brachyrhynchos brachyrhynchos, Bonasa umbellus, Gallus domesticus, Melopsittacus undulatus, and Serinus canarius) at 28 and 48 days postinfection. The crows, ruffed grouse, and domestic chicks were laboratory raised while the budgerigars and canaries were from pet stores. One canary that was further examined at 180, 360, 540, 730, and 910 days postinfection still had detectable numbers of trypanosomes in its blood.
Systemic listeriosis in caged canaries (Serinus canarius)