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Thirteen Tammar wallabies (Macropus eugenii) were dosed orally with 500, 1000 or 10,000 oocysts of Toxoplasma gondii, as part of a vaccination trial. Eleven animals died of acute toxoplasmosis 9 to 15 days after challenge. The lesions were similar in all animals, consisting of foci of necrosis and inflammation in the intestines, lymphoid tissue, adrenal cortex, heart, skeletal muscle and brain, and severe generalised pulmonary congestion and oedema. Free and intracellular tachyzoites of Toxoplasma were associated with the lesions. The remaining 2 animals had shown no signs of disease when euthanased four months after challenge. Small, focal, non-suppurative inflammatory lesions were seen in brain, heart and skeletal muscle of these animals and chronic Toxoplasma infection was confirmed by mouse inoculation.

Seven of 30 canaries in an aviary in New Zealand developed ophthalmic problems. Clinically, 5 birds had unilateral and 2 birds had bilateral lesions characterized by conjunctivitis, crusty exudates on eyelids, and collapse of the eyeball. Microscopic lesions in 12 of 14 eyes examined included inflammation of the choroid and retina, with osseous replacement of the globe in some. Numerous Toxoplasma gondii tachyzoites were seen in the detached retina and vitreous humor of acutely affected birds. The diagnosis of toxoplasmosis was confirmed by immunohistochemical staining with T gondii antiserum. Affected birds had encephalitis, and T gondii was localized in the brains of these by immunohistochemical examination and by use of bioassays in mice. Toxoplasmosis should be considered in differential diagnosis of ophthalmitis in canaries.

A penguin (Eudyptula minor) from Tasmania, Australia, died following a 3-day illness. The liver and spleen parenchyma contained grossly visible foci of discoloration. Numerous tachyzoites of Toxoplasma gondii were seen associated with necrosis in sections of liver and spleen. The diagnosis was confirmed by immunohistochemical staining of parasites. This apparently is the first report of fatal toxoplasmosis in a penguin.

This report describes toxoplasmosis lesions in Australian marsupials. Clinical signs, necropsy findings and histopathological changes are summarized for 43 macropods, two common wombats, two koalas, six possums, 15 dasyurids, two numbats, eight bandicoots and one bilby. Animals either died suddenly without clinical signs or exhibited signs associated with respiratory, neurological or enteric disease. At necropsy, many marsupials had no visible lesions. Where present, common necropsy findings included pulmonary congestion, oedema and consolidation, adrenal enlargement and reddening, haemorrhage and ulceration of stomach and small intestine, and lymphadenomegaly and splenomegaly. Microscopically, affected lungs showed interstitial pneumonia and macrophage accumulation. Myocardial, skeletal and smooth muscle necrosis and neutrophilic inflammation were common. Organs had focal necrosis and/or fibrosis and lymphoid infiltrates. Toxoplasma gondii tissue cysts were common in muscle and nervous tissue. Free tachyzoites were commonly present in areas of necrosis. Selected sections from four macropods, two koalas, two dasyurids, one wombat and one possum stained specifically with avidin-biotin complex and anti-Toxoplasma gondii serum.

Toxoplasma gondii-like organisms were seen in the heart, kidney, liver, lung, lymph node, spleen, small intestine, and stomach from 2 koalas that died suddenly in a fauna park in Sydney, Australia. Diagnosis was confirmed by immunohistochemical staining. This is the first confirmed report of toxoplasmosis in an arboreal marsupial.