CANINE CUTANEOUS NEOSPOROSIS - CLINICAL IMPROVEMENT WITH CLINDAMYCIN

Progranulomatous dermatitis caused by the protozoan parasite Neospora caninum was diagnosed in a 12-year-old Golden Retriever dog. Multiple draining nodules were located in the skin of the head and thorax. Nume rous tachyzoites of N. caninum were found in histologic sections of th e biopsy tissue from the cutaneous nodules and the diagnosis was confi rmed by immunohistochemical staining and by electron microscopic exami nation. The dog had a 1:3200 serum antibody titer to N. caninum in the indirect fluorescent antibody test. The cutaneous lesions resolved af ter a 45-day treatment with clindamycin hydrochloride. The dog eventua lly died because of lymphosarcoma and also had a latent infection with Toxoplasma gondii. Neospora caninum could not be demonstrated by bioa ssays in cell culture or mice inoculated with canine tissue obtained a t necropsy. Only degenerating N. caninum tachyzoites were seen in skin tissue taken at necropsy. These observations indicate that neosporosi s should be considered in the differential diagnosis of pyogranulomato us dermatitis in dogs and that clindamycin may be an effective drug fo r treating cutaneous neosporosis.