Acute toxoplasmosis in a gray fox (Urocyon cinereoargenteus)

Toxoplasmosis was diagnosed in a gray fox (Urocyon cinereoargenteus) found moribund in Lake Loundes Park, Mississippi. There was almost total necrosis of mesenteric lymph nodes, focal hemorrhage and necrosis in the brain. Lesions in all of these organs were associated with numerous Toxoplasma gondii tachyzoites. Tissue cysts were seen in the brain. Organisms reacted with anti-T. gondii serum in an avidin-biotin immunohistochemical test. There was no evidence of concurrent distemper or rabies virus infection. Hammondia heydorni-like schizonts and gamonts were seen in sections of intestinal epithelium.