Cherry Eye occurs when the dog’s third eyelid moves out of position and becomes inflamed. The third eyelid is a membranous structure which is located in the inside corner of the eye. When swollen and inflamed, the third eyelid looks like a cherry, thus the name. One or both eyes can be affected, with higher number of cases occurring among younger dogs. While the exact cause of cherry in dogs is not known, some breeds show a genetic predisposition to the problem. These breeds include Lhasa Apso, Shih Tzu, Beagle, Saint Bernard, Boston terrier, and Chinese Shar-Pei among others. In some cases, the inflammation of the third eyelid occurs as a sequel to inflammatory processes. The protruding mass that appears like a cherry is the most distinct symptom that can be observed. Affected dogs may have reddish or inflamed eyes; there may also be increased tearing and pus-like discharge from the affected eye. Your Thousand Oaks, CA veterinarian may conduct a battery of tests to identify the underlying cause. To learn more, click here.