“Cherry eye" is a common term for prolapse of the third eyelid gland. Dogs have a 'third eyelid' that contains a tear gland and is located in the corner of each eye. Under normal circumstances, this gland is not visible and produces approximately 60% of the tear film, therefore having an essential role in keeping the surface of the eye wet. When this gland prolapses or "pops out", the condition is known as "cherry eye”.
The prolapse of the third eyelid gland appears as a red swollen mass (named by its resemblance to a cherry) on the lower eyelid near the nose or muzzle. The "cherry eye" may be large and cover a significant portion of the cornea or it may be small and appear only periodically.
Cherry eye can occur in many breeds of dogs but is most common in young Cocker Spaniels, Lhasa Apsos, Shih Tzus, Bulldogs, Mastiffs, Beagles, Shar-pei, Pekingese, Boston Terriers, and St. Bernards. Although the problem can occur at any age, it is most common in animals 2 years of age or younger. The condition usually affects both eyes but not necessarily at the same time. The second eye often becomes affected after an interval of a few weeks to months.
Treatment involves surgical replacement of the third eyelid gland. It is important to treat the condition as soon as possible in order to minimize damage. Removal of the gland is not a suitable option as it predisposes the eye to low tear production (‘dry eye’) later in life.
In most cases, the gland returns to normal function within a few weeks of surgery. A small percent of cases may experience a re-prolapse of the third eyelid gland and require additional surgery.