Blastomycosis in dogs: 115 cases (1980-1995)

To characterize diagnostic results, treatment, and outcome of dogs with blastomycosis during a 15-year period in Louisiana.

Retrospective case series.

115 dogs with blastomycosis.

Medical records were reviewed for dogs with blastomycosis examined between 1980 and 1995. Additional data were collected from the state veterinary diagnostic laboratory, via telephone interviews of owners, and by use of a random survey of the hospital population.

Blastomycosis was detected mainly in young, large-breed dogs. Proximity to a body of water was a significant risk factor for affected dogs. Most dogs were affected in January and August through October. Clinical signs and results of physical examination reflected the multisystemic nature of the disease. Commonly affected systems included the respiratory tract and lymphatic, ocular, and cutaneous systems. Nodular interstitial and interstitial patterns were common findings on thoracic radiographs. Cytologic examination was successful in identifying organisms in samples from vitreous, skin, and lymph nodes. Similar results were achieved for dogs treated with a combination of amphotericin B and ketoconazole, compared with dogs treated with itraconazole.

Results of this study should assist veterinarians with the recognition and management of blastomycosis in dogs. Blastomycosis should be considered as a differential diagnosis for large-breed dogs that live close to a body of water in areas in which the disease is endemic or in dogs with a history of being transported to endemic areas that subsequently develop signs of pulmonary, ocular, lymphatic, or cutaneous disease. Treatment with itraconazole was as effective as treatment with a combination of amphotericin B and ketoconazole.