Dogs have an additional eyelid called a third eyelid. At its base is a gland that helps keep the eye moist. Sometimes this gland moves out of position and protrudes from behind the eyelid. This pink or red mass sticking out of the dog’s third eyelid can be an alarming sight to a dog owner. Veterinarians call this condition cherry eye or in medical terms, a prolapsed lacrimal tear gland or an eyelid protrusion. The good news is that it is a treatable condition.1
Symptoms of Cherry Eye
When a dog has cherry eye, the protruding pink or red fleshy mass is a visible sign that something is wrong with your pet’s eye. The tissue has an oval shape and usually appears suddenly in the corner of the eye closest to the nose. However, there are other visible symptoms. Before the red mass appears, owners may notice watering or a pus-like discharge from one or both of the dog’s eyes. Most dogs also experience swelling and irritation of the affected eye, and it may appear dry and irritated. Sometimes cherry eye develops in one eye, but it can also develop in both. The mass is sometimes small, barely covering the cornea, which is the clear dome that protects the surface of the eye. However, other dogs may experience a large mass that covers the cornea entirely.2
Cherry Eye is Not an Eye Infection
An infection occurs when a foreign agent, such as a microorganism, works its way into a living body. It requires a scrape or cut to develop. If left untreated, cherry eye can lead to infections; however, that isn’t what causes the red protrusion. Most vets blame the development of cherry eye on weak ligaments that connect the third eyelid to the rest of the eye, not an infection. These weak ligaments break, and the lid slips forward, causing it to protrude from the eye. This red mass is what owners see.3
The Importance of the Third Eyelid
A dog’s eyes are similar to a human’s. It’s primarily their highly developed night vision, well-developed ability to detect movement and the third eyelid–the nictitating membrane–that makes us different. The lower eyelids usually conceal it, but it is visible if the eye becomes irritated or develops certain diseases. The third eyelid not only creates 30% of tear production, but it also protects the dog’s eyes during hunts or fights with other animals. When it’s healthy, the third eyelid is a whitish pink color.4
Anatomy of the Dog’s Eye
The third eyelid starts in the inner corner of the eye and covers the eye diagonally. Like humans, the dog’s upper and lower lids behave as a shield, protecting the eyes from foreign objects such as dust or dirt. The dog’s tear film keeps the eye lubricated with oil, water, and mucus. The outer eyelids’ glands produce the oil. The pink part inside the eyelids, the conjunctiva creates the mucus. The lacrimal or tear glands produce the water. Dogs have two of these glands in each eye, one above the eye and another in the third eyelid. If the tissue fibers that hold the lacrimal gland in place weaken, the gland drops down. When the lacrimal gland isn’t in the normal position, it doesn’t circulate the blood needed and starts to swell, and it appears as a visible red mass.5
Breeds Most Likely to Develop Cherry Eye
Younger dogs or puppies are more likely to develop the condition, but the cause is rooted in the genetics of certain canine types. Smaller breeds such as cocker spaniels, French and English bulldogs, beagles, Lhasa apsos, Shih Tzus, and Boston terriers have weaker tissue fibers that hold the lacrimal gland of the third eye in place. These breeds are more likely to develop cherry eye. Larger breeds, including Saint Bernards, Newfoundlands, and bloodhounds are also prone to the condition. However, cherry eye can affect any breed.6
Does Cherry Eye Cause Discomfort?
Most dogs experience some level of discomfort due to cherry eye. They may experience outright pain caused by dryness in the eyes. You may notice your dog squinting. They may paw or scratch at their face to relieve the discomfort, but this can cause further irritation. Your pet may rub their face across the grass, floor, or furniture to find relief. A dog who is usually playful may not show interest in their toys. Some dogs lose their appetite. When a dog is in pain, they may seek more attention and comfort from you than they normally do. Other dogs hide, preferring to be alone when in pain. Drooping ears and whimpering are also signs that they are experiencing pain or discomfort.7
Diagnosing Cherry Eye
Because untreated cherry eye can cause long-term health problems such as blindness or lead to bacterial or viral infections, it is crucial to seek veterinarian care for your pet as soon as possible. A vet’s visual exam can usually confirm cherry eye. They don’t usually perform any invasive testing to confirm the diagnosis. In rare cases, the vet might see symptoms of another disorder or condition such as cancer and administer additional testing.8
What if I Can’t Get My Dog Into a Vet Right Away?
Sometimes, getting to the vet isn’t possible and must be delayed. In its early stages, owners can use a combination of warm, moist cloths and dog-safe eye drops. Although some pet owners have successfully treated their pet by gently massaging the prolapsed tear gland until it falls back into place, there is no guarantee that the treatment is permanent or that it won’t recur. If a dog experiences cherry eye in one eye, they’ll likely experience it in the other one. Pet health experts advise seeking professional veterinary care even after successful home treatment.9
Older Methods of Treatment
In the past, it was a common practice to remove the prolapsed gland. However, over time, animal health researchers discovered that this practice led to serious dry-eye conditions. These issues required daily medical treatments to keep the eye moist and the dog comfortable. Owners found the treatments not only frustrating but also expensive. Soon after the removal of the gland, dogs, especially older ones, often developed a thick, yellow discharge. This caused a condition called keratoconjunctivitis sicca, which is a dryness of the membrane that covers and protects the eye.10
Today, veterinarians recommend other surgical treatments instead of removing the gland. The most common treatment is tucking, using a single stitch to take the lacrimal gland back in its normal position. However, this type of surgery is infamous for its failure. The stitch can untie and scratch the dog’s eye, and a veterinarian must then remove it. Most vets use a newer surgical technique called imbrication. Although it is more difficult, it has higher success rates. Surgeons remove a wedge of tissue over the actual gland. Dissolving stitches close the gap and push the gland back into place. As with any surgical procedure, there are complications. Talk with your veterinarian about the different treatment options to decide which one is best for you and your pet.