Canine sporotrichosis in Rio de Janeiro, Brazil: clinical presentation, laboratory diagnosis and therapeutic response in 44 cases (1998-2003)

A sporotichosis epidemic involving forty-four dogs in the Metropolitan area of Rio de Janeiro is described. Solitary skin lesions were noted in 18 dogs (40.9%), 2-4 such lesions were observed in 17 animals (38.6%), and nine (20.5%) animals had five or more lesions. Twenty-five (56.8%) animals had single ulcerated skin lesions on the nose and nine (20.5%) showed nasal mucosal involvement (three of which also has a skin lesion). Respiratory symptoms were observed in 17 (38.6%) dogs and were found to be the most common extracutaneous signs of infection. Anemia, leukocytosis with neutrophilia, hypoalbuminemia and hyperglobulinemia were the most frequent hematological abnormalities. Histopathological analysis of skin biopsies in most cases revealed granulomatous reactions characterized by histiocytic hyperplasia and neutrophil infiltration. Yeast-like cells were observed in seven (16.7%) of 42 dogs examined histologically. During the study, eight (18.2%) animals were lost to follow-up and three (6.8%) were submitted to euthanasia. Of the remaining 33 dogs, five (15.2%) presented spontaneous regression of the lesions, 26 (78.8%) were cured after treatment, and two (6%) continue to be treated. The present cases indicate that many dogs with sporotrichosis respond well to treatment and in a few dogs, the disease may be self-limiting.