Successful management of refractory cough with the leukotriene receptor antagonist zafirlukast in a dog with chronic bronchitis: a case report

A 7-year-old spayed female Pomeranian dog was evaluated for a 6-month history of intractable coughing and dyspnoea. The cough was unresponsive to antibiotics and a bronchodilator medication prescribed by the previous animal hospital. No abnormalities were identified on the blood work, echocardiography and radiography. However, computed tomography revealed mild bronchiectasia. Based on the history, physical examination and non-specific diagnostic imaging findings, the dog was diagnosed with chronic bronchitis. The cough failed to resolve, despite an attempt to manage it with prednisolone, theophylline, codeine and N-acetylcysteine. With the owner’s consent, we stopped all previous medications and finally tried the leukotriene receptor antagonist zafirlukast. The cough progressively improved and had mostly resolved four weeks after starting the administration of zafirlukast. The dog remained in complete remission without recurrence for seven months. This case report is the first to describe the successful long-term management of chronic cough with zafirlukast in a dog.