Reactivated toxoplasmosis in a FIV-positive cat

An eight-year-old, FIV-positive, domestic shorthaired cat presented with we ight loss and progressive neurological signs. Thoracic radiographs showed m ultiple pulmonary nodules and the cat was euthanased. Squash preparations o f the lung lesions were made at necropsy and were cytologically consistent with carcinoma. Histologically, the cat had pulmonary and cerebellar toxopl asmosis. Tachyzoites were difficult to demonstrate in the lung lesions both histologically and cytologically. This case demonstrates the difficulties in ante-mortem diagnosis of toxoplasmosis in the cat.