Unless a systematic approach is used, evaluation of a patient with rhinitis can be frustrating to the veterinary practitioner. A complete differential list for canine rhinitis should include infectious, inflammatory, neoplastic, and traumatic causes. Other causes of rhinitis include dental disease, parasitic infestation, and ciliary dyskinesia. Diagnostic techniques that should be considered when evaluating a patient with rhinitis include obtaining a complete history, performing a thorough physical and oral examination, evaluating the patient's coagulation abilities, cytology and culture of exudate, nasal radiographs, and rhinoscopy. This article describes the pathogenesis and treatment of the various causes of canine rhinitis.