Cherry eye in dogs is a condition in which the third eyelid falls down or prolapses out of place and is then visible in the corner of the dog's eye. Unlike people which only have 2 eyelids, dogs have another eyelid that is normally invisible otherwise known as the nictitating membrane. The function of this third eyelid is to help protect and moisturize the eye through its tear gland.
Often the large red mass of tissue in the corner of the dog’s eye is the only symptom that the pet owner sees. Cherry eye rarely occurs in both eyes at a time. Rather the cherry eye just pops out in one eye. The eyelid does not gradually slip out of place, it happens over a short period of time, and pet owners are often shocked to see that their dog which looked fine a few minutes ago now has a large red blob in the corner of the eye.
Cherry eye can be treated through topical steroids or antibiotics, or through surgery. Topical steroids and antibiotics on the cherry eye will reduce infection and inflammation. However this type of treatment is rarely successful for long periods of time.