Prolapsed Gland of the Third Eyelid - "Cherry Eye"
The third eyelid is a pink structure just barely visible in the inner corner of each eye (toward the nose) in a dog or cat. This eyelid slides out horizontally when the animal blinks and helps to protect the eye. In addition, it houses the major tear gland for the eye. The tears produced from this gland help to keep the surface of the eye moist and prevents infection.
Some third eyelid glands prolapse due to trauma to the eye; for example, rough play with another dog or an eye injury from a toy. There may also be a genetic link to a congenital weakness of the gland of the third eyelid. Certain breeds are more predisposed to this condition and it occurs most often in young dogs (usually less than 2 years of age). These breeds include: Cocker spaniels, Bulldogs, Beagles, Bloodhounds, Lhasa apsos, and Shih tzus (although any breed can be affected). "Cherry eye" can occur in cats, but is rare.
A "cherry eye" appears most often as a small, smooth, pink bump in the inner corner of the eye. It may appear in one eye or both eyes (it is not uncommon for one eye to be affected first followed months to years later by the other eye). If the condition has just occurred, some dogs may also show symptoms of squinting, pawing at the eye, eye discharge, or a red and irritated eye.
First, have your veterinarian examine the eye. Depending on the exam findings, eye tests to rule out corneal damage or medications to fight infection may be needed.
In most cases, a "tacking" surgery is recommended in order to return the tear gland to its normal position. The long term consequence of leaving the gland prolapsed is the possible loss of a majority of tear production for the affected eye. (There are other tear glands for the eye, but the third eyelid tear gland produces up to 50% of the total tears). If tear production decreases, the eye may "dry out" causing pain, irritation, and infection that requires life long treatment.
The tacking surgery is the best option because it returns the third eyelid gland to its normal position and helps to maintain tear production. However, complications of this procedure include recurrence (may happen in up to 25% of cases).
Another surgical procedure involves removal of the prolapsed gland. This method returns the eye to a normal appearance, but patients run the same risk of "dry eye" because the tear gland is gone. This procedure is usually recommended only for those patients who have tried the tacking procedure and the prolapse has recurred.