Dog owners may notice a "cherry red" lump in the corner of their dog's eye(s) and wonder what it is and what to do about it. What causes this condition, and how is it treated?
For the quick version, please see the Cherry Eye Glossary Entry.
Dogs have two tear-producing (lacrimal) glands in each one. One is located in the upper lid, one is the lower lid in a membrane called the third eyelid. The third eyelid is also called the nictitating membrane.
Cherry eye is the common term for a prolapse (eversion) of the gland of the third eyelid of dogs. When the gland prolapses, the usually moist tissue is exposed to air and other irritations (i.e. a paw) and blood supply to the gland is interrupted. This produces a very red lump in the inside corner of the eye, or eyes if both are affected. This is likely where the condition "cherry" eye gets its name.
The cause of cherry eye is not fully known, but thought to be a weakness in the eyelid tissue that normally holds the gland in place. Genetics also play a role. Some breeds, such as Cocker Spaniels, Shar Peis, Bulldogs, Beagles and Boston Terriers, have a higher incidence of this condition.
This condition is not usually painful to the dog, but is unsightly and will interfere with the normal tear production for that eye. This third eyelid gland is thought to produce approximately 30% of the tear production for the eye.
Treatment can be one of two options: replace the eyelid and try to save the gland, or remove the gland. A possible risk of replacement of the gland is a recurrence of the condition or the sutures causing a problem for the eye. The problem with removal of the gland is the development of dry eye, called keratoconjunctivitis sicca (KCS), later in life.
As animals age, tear production decreases. Other eye conditions or injuries may also reduce tear production. By preserving the gland early in life, it will benefit the dog in the senior years.
Years ago, many vets removed the gland for treatment of Cherry Eye. It is a relatively simple and quick surgery. Now, recognizing the importance of preserving tear production later in life, preservation of the gland is the goal. A couple of different surgical methods have been utilized to replace the gland and prevent prolapse. Your veterinarian may do this surgery or refer your pet to a veterinary ophthalmologist. This is a veterinarian who has had advanced training and certification in Ophthalmology. To learn more about veterinary ophthalmologists, please visit the American College of Veterinary Ophthalmologists (ACVO) website.