Dogs and cats have 3 eyelids: upper lid, lower lid, and one that is attached inside the other lids at the inside corner of the eye socket. This third eyelid serves to protect the eye from injury by closing over the eye to give a second covering of the eye.
On the inside of this third eyelid, there is a small lymph node and small gland that produces tears. The tears produced aid in lubrication of the eye.
A condition exists where this small gland becomes inflamed and swollen. Once swollen, the tissue of this gland then protrudes out over the free edge of the third eyelid. This condition is sometimes called cherry eye, because the reddened, swollen tissue resembles a cherry.
CAUSE of this condition is not known. An infection or allergic reactions may sometimes cause the condition. There is a tendency for the condition to occur in the other eye at some future date.
TREATMENT of this condition may be medical or surgical. Often times the condition is first treated topically with anti-inflammatory medications in an effort to avoid surgery. If medical therapy is not effective, then surgery to either remove part of the gland or replace the gland into its normal position is recommended.