A 9-year-old cat was presented to a primary care veterinarian for examination of 4 cutaneous nodules. Lacking a definitive diagnosis, the cat was treated with enrofloxacin and glucocorticoids. Within a short time, it developed hundreds of ulcerated and nonulcerated nodules and became polyuric, polydipsic, thin, and hypothermic. It was also in severe respiratory distress, had bilateral retinitis, and was nearly comatose at the time of referral examination. Emergency care was administered and diagnostic testing performed, but the cat died shortly after presentation. Radiographs revealed severe pneumonia, and bronchoalveolar lavage (BAL) showed mucus, necrotic matter, and macrophages. Fine-needle aspiration of the nodules and BAL revealed inflammatory cells and many small-sized organisms, suggestive of Toxoplasma gondii. Histologic examination of tissue revealed diffuse, deep necrotic dermatitis/panniculitis and protozoal organisms. Organisms were also found in other internal organs. Polymerase chain reaction testing was used to differentiate T. gondii infection from that of Neospora caninum.
COMMENTARY: Disseminated nodular skin disease is rare, and this case report highlights yet another possible differential diagnosis. The major take-home message is to take a biopsy on suspicious lesions as soon as possible and avoid immunosuppressive drugs until infectious agents have been ruled out. This is the third report of disseminated cutaneous toxoplasmosis in a cat. In 1 cat, the cutaneous toxoplasmosis developed after treatment with cyclosporine for feline atopy. When presented with a cat with diffuse nodular disease, the most appropriate immediate diagnostic tests are fine-needle aspiration, excisional skin biopsy for culture, and skin biopsy for histopathologic evaluation. The author has seen 1 other case in which the cat presented with hundreds of nodules and was diagnosed with disseminated cutaneous Cryptococcus.
Feline cutaneous toxoplasmosis: A case report. Anfray P, Bonetti C, Fabrizio F, et al. VET DERMATOL 16:131-136, 2005.