Polyarthritis associated with visceral leishmaniasis in a juvenile dog.

Canine visceral leishmaniasis (CL) is a zoonosis and a chronic systemic disease characterized by a wide spectrum of clinical signs, including, in rare occasions, polyarthritis. This report describes a case of CL in an 8-month old male boxer dog with a history of lameness, fever and lymphadenopathy. A definitive diagnosis of CL was based on the observation of the Leishmania amastigotes seen concomitantly, and for the first time, in the lymph nodes aspiration smears (in macrophages), synovial fluid (in macrophages and neutrophils) and blood (in neutrophils). Despite this extensive dissemination of the parasite, the animal was successfully treated with a multi-step combination of meglumine antimoniate, aminosidine and allopurinol.