Toxoplasmosis in Macropodids: A Review

Toxoplasmosis is a well-described disease entity that causes significant morbidity and mortality in both captive and free-ranging macropodids. The clinical presentation of toxoplasmosis in macropodids is variable, which reflects the multiple body systems affected by this disease. Animals may die without exhibiting premonitory signs or after the acute development of nonspecific signs of illness. In more chronic cases, clinical signs include neurologic deficits, blindness, respiratory signs, and, in some cases, diarrhea. Histologic lesions can be extensive and affect the pulmonary parenchyma, cardiac and skeletal muscle, lymph nodes, spleen, gastrointestinal tract, adrenal glands, pancreas, central nervous system, liver, and kidney. An antemortem diagnosis can be challenging, although a range of serologic tests are available. Treatment is frequently unrewarding, although recent evidence suggests that the anti-protozoal drug atovaquone may be effective in treating acute cases and eliminating infection. Attempts to vaccinate macropodids against toxoplasmosis have been unsuccessful, and preventive measures are limited to preventing exposure to sporulated oocysts in the environment.