Central nervous system toxoplasmosis in Roller canaries

Several birds in a flock of 40 Roller canaries (Serinus canaria) from an outdoor aviary in Victoria, Australia, developed central nervous system signs that included blindness, nystagmus, ataxia, and head rotation. Four died, and four were euthanatized. Two euthanatized birds were submitted for microscopic examination of tissues. Brain lesions in both birds consisted of scattered foci of nonsuppurative meningoencephalitis with gliosis, mild to moderately extensive lymphocytic/plasmacytic perivascular cuffs, and a patchy increased prominence of cerebral blood vessels associated with hypertrophy of the vascular endothelium and/or thickening of their connective tissue walls. These lesions were associated with the presence of Toxoplasma gondii tissue cysts. Lesions in the eyes of both birds were bilateral and consisted of severe plasmacytic/granulomatous ophthalmitis. Surviving birds were treated with trimethoprim and sulfadiazine, no subsequent deaths occurred, and no new cases developed over an 8-month period.