Fiiaroides osieri in a dog

Summary The symptoms, diagnosis, treatment and necropsy findings in a Filaroides osleri infection in a dog are described. Changes in respiratory function before and after treatment are recorded and the possible significance of bronchospasm as a cause of dyspnoea is discussed. Although diagnosis was made initally by finding larvae in bronchial washings, endoscopy is considered the most reliable means of diagnosis. Treatment with thiabendazole, levamisole and fenbendazole appeared to suppress larval production but failed to kill adult F. osleri.