Simple SummaryFlat-faced (brachycephalic) dogs have increased in popularity despite growing awareness that extreme facial conformation with very bulging eyes compromises their health. Medial canthoplasty (MC) is a commonly performed surgical procedure in flat-faced dogs to improve their facial anatomy with the aim of decreasing eye irritation and discharge and reducing the likelihood of painful ulceration on the surface of the eye (cornea). This study analysed data from flat-faced dogs that were recommended and/or underwent MC. In addition, a questionnaire of owners’ perceptions, including eye problems before and after the surgery, and overall satisfaction were collected. Nearly three-quarters of the dogs recommended surgery had a history of, or actively had, corneal ulceration. Under half of the dogs recommended MC went on to have surgery and three quarters of these were Pugs. MC significantly reduced eye discharge, frequency of owners cleaning around their dog’s eyes, eye irritation and corneal ulceration with minimal complications and high owner satisfaction. These results demonstrate the value of MC surgery to improve the quality of life of flat-faced animals.AbstractBrachycephalic breeds have increased in popularity despite growing awareness of their predisposition to a wide range of conformation-related diseases. The extreme facial conformation of many popular brachycephalic breeds compromises their ocular surface health, increasing the risk of painful corneal ulceration. Medial canthoplasty (MC) is a surgical procedure to address ocular abnormalities in brachycephalic dogs, which are collectively referred to as brachycephalic ocular syndrome (BOS). This study retrospectively reviewed the records of dogs recommended MC at a referral hospital between 2016 and 2021. A questionnaire was designed to identify owners’ perceptions pre- and post-operatively. From 271 brachycephalic dogs recommended MC, 43.5% (118/271) underwent surgery and 72.0% (85/118) were Pugs. The majority of dogs (73.7%, 87/118) that underwent surgery had current or historical corneal ulceration. Follow-up was available in 104 dogs, of which 5.7% (6/104) had corneal ulceration post-operatively. Sixty-four owners completed the questionnaire and reported post-operative corneal ulceration in 12.5% of dogs (8/64), reduced ocular discharge (70.8%, 34/48), reduced ocular irritation (67.7%, 21/31) and less periocular cleaning (52.5%, 32/61). Owners were satisfied with the clinical (85.9%, 55/64) and cosmetic (87.5%, 56/64) outcome. In conclusion, MC has high clinical relevance for the surgical management of BOS, restoring functional conformation and improving the quality of life of affected dogs.