A 10-year-old, castrated male domestic short hair cat was presented to the Small Animal Clinic at the Western College of Veterinary Medicine with a presenting complaint of chronic, ocular discharge from the left eye. Ocular examination confirmed epiphora and mucopurulent discharge but there were no apparent reasons for the ocular discharge, and nasolacrimal obstruction was suspected. The cat had swelling of the left side of the face, severe periodontal disease and a fractured upper left canine tooth with pulpal exposure. Dacryocystorhinography revealed narrowing of the nasolacrimal duct above the root of the fractured upper left canine and dental radiographs showed a severe periapical lucency at the apex of the upper left canine tooth. The fractured canine tooth was removed. Subsequently, the ocular discharge and facial swelling resolved. After 2 years, the epiphora has never reoccurred. This is a noteworthy case because a suspected root abscess resulted in extralumenal compression of the nasolacrimal duct, which shows the importance of a thorough oral examination when nasolacrimal obstruction is evident.