Cherry Eye (Prolapse of the Gland of the Third Eyelid) in Dogs

TL;DR. Cherry eye is a common, highly treatable condition in young dogs where a tear-producing gland in the corner of the eye pops out of place, requiring surgical repositioning to protect long-term eye health.

The third eyelid gland plays a critical role in tear production; when its anchoring tissue fails, it prolapses outward.

What is it?

To understand "cherry eye," it helps to first understand the unique anatomy of your dog's eyes. Unlike humans, dogs possess three eyelids. In addition to the upper and lower eyelids, they have a third eyelid—scientifically called the nictitating membrane—located in the inner corner of each eye. This third eyelid acts like a protective windshield wiper, sweeping across the cornea to clear away debris and distribute moisture.

Nestled at the base of this third eyelid is a specialized tear gland. This gland is an absolute powerhouse, responsible for producing approximately 30% to 50% of the watery portion of your dog's tear film. Tears are vital; they lubricate the eye, deliver essential oxygen and nutrients to the cornea, and wash away potential pathogens.

Cherry eye occurs when the connective tissue anchor that holds this gland securely in place weakens, stretches, or tears. Deprived of its anchor, the gland pops out of its normal position, flipping upward and outward over the edge of the third eyelid. Once exposed to the open air, the delicate glandular tissue quickly becomes irritated, inflamed, and swollen. It takes on a bright red or pink, rounded appearance in the inner corner of the eye, which is how the condition earned its common name.

While cherry eye is rarely a sudden life-threatening emergency, it is a significant health concern. An exposed, swollen gland cannot produce tears effectively. Furthermore, chronic exposure leads to inflammation, tissue damage, and secondary infections. If left untreated, or if the gland is surgically removed rather than repaired, your dog is at an extremely high risk of developing keratoconjunctivitis sicca (KCS), commonly known as "dry eye." Dry eye is a painful, chronic condition that requires lifelong, expensive daily medication to prevent corneal scarring and blindness.

Causes & risk factors

Cherry eye is primarily a developmental and genetic condition. It is not caused by trauma, poor hygiene, or infections, though these issues can occur secondary to the prolapse. Instead, affected dogs are born with a congenital weakness in the fibrous connective tissue that anchors the gland to the orbital rim.

This structural weakness is highly age-dependent. Cherry eye is overwhelmingly a disease of young dogs, typically manifesting before a dog reaches their first birthday. A leading veterinary surgery reference notes:

"Prolapse of the gland of the third eyelid (also known as "cherry eye") is a common occurrence in dogs less than 1 year of age."

Because the underlying cause is genetic, certain breeds are highly predisposed to developing cherry eye. Breeds with shorter muzzles (brachycephalic breeds) or those with loose, droopy facial skin are at the highest risk. The Boston Terrier, English Cocker Spaniel, and English Bulldog are among the most frequently affected breeds. In these dogs, the shape of the skull and the conformation of the eye socket place additional physical stress on the already weak connective tissues of the third eyelid.

Signs to watch for

Recognizing cherry eye is generally straightforward because the physical signs are highly visible. However, you should also watch for signs of secondary irritation and discomfort.

• Protrusion of a red or pink, smooth, round mass from the inner corner of the eye (Cardinal): This is the classic "cherry" appearance. It may start out appearing intermittently—popping out when the dog is excited or tired and then disappearing—before eventually remaining permanently prolapsed.
• Conjunctivitis (Common): The surrounding tissues of the eye will often look red, bloodshot, and swollen due to localized inflammation.
• Ocular discharge (Common): You may notice watery tearing, or a thicker, mucus-like discharge accumulating around the eye.
• Pawing or rubbing at the face (Common): The swollen gland feels like a foreign object in the eye, prompting dogs to rub their eyes against carpets, furniture, or with their paws.
• Squinting or blinking excessively (Rare to Common): This indicates active pain or corneal irritation, often secondary to dryness or self-trauma.

Cherry eye presents as a smooth, round, red mass in the inner corner of the dog's eye.

While a prolapsed gland is not an immediate emergency, you should seek veterinary care promptly. If your dog is squinting heavily, rubbing their eye aggressively, or if the discharge becomes thick, yellow, or green, these are red flags indicating a potential corneal ulcer or a severe secondary bacterial infection.

How vets diagnose it

Diagnosing cherry eye is highly straightforward. Your veterinarian will perform a thorough physical and ophthalmic examination.

• Visual Inspection: This is the gold standard for diagnosis. The characteristic appearance of a smooth, pink mass arising from the bulbar (inner) side of the third eyelid is virtually diagnostic on its own. Your vet will easily differentiate this from other ocular masses, such as tumors or cysts, based on your dog's age, breed, and the specific anatomical location of the swelling.
• Schirmer Tear Test (STT): Your vet will place a small, calibrated paper strip inside the lower eyelid for one minute to measure tear production. This test is vital to determine if the prolapsed gland has already suffered a drop in tear output, and to establish a baseline before any surgical intervention.
• Fluorescein Stain Test: Your vet will apply a harmless green dye to the eye to check for corneal ulcers. Because dogs with cherry eye often rub their faces, scratches on the clear surface of the eye are common and must be treated concurrently.
• Intraocular Pressure (IOP) Measurement: Using a specialized device called a tonometer, the vet will check the pressure inside the eye to rule out glaucoma or internal inflammation (uveitis).

Your veterinarian will perform a full eye exam, including tear testing and pressure checks, to ensure overall eye health.

Treatment options

There is only one highly effective, long-term treatment for cherry eye: surgical replacement. Medical therapy, such as anti-inflammatory or antibiotic eye drops, may temporarily reduce swelling and discomfort, but it will not repair the broken connective tissue anchor. Once the drops are stopped, the gland will almost always prolapse again.

Historically, veterinarians sometimes treated cherry eye by simply cutting the gland out (excision). Today, excision is strongly discouraged and considered below the standard of care, except in rare cases of glandular neoplasia (cancer). Removing the gland deprives the eye of a massive portion of its tear-producing capacity, almost guaranteeing the development of painful, chronic dry eye (KCS) later in life.

Modern veterinary surgery focuses on preserving the gland by tucking or anchoring it back into its proper anatomical position. Two primary surgical techniques are widely accepted:

1. The Pocket Technique (Imbrication Technique)

This is the most common surgical repair method. The surgeon makes two parallel, shallow incisions in the conjunctiva (the pink mucosal lining) on either side of the prolapsed gland. The gland is then gently tucked down into this newly created pocket. The surgeon sutured the edges of the pocket closed over the gland, burying it back where it belongs.

As described in a leading veterinary surgical text:

"...area at both ends of the gland that is not incised to allow secretions from the gland to exit onto the ocular surface and not cause cyst formation. The incisions are then closed so that the third eyelid conjunctiva covers the gland."

This technique is highly successful because it preserves the gland's ability to secrete tears freely onto the eye while keeping it physically secured.

2. Orbital Tacking (Anchoring Technique)

In some cases, particularly when the pocket technique is not ideal or has failed, the surgeon may choose to anchor the gland directly to the surrounding skeletal structures. The surgeon places a suture through the gland and secures it to the orbital periosteum (the tough connective tissue membrane covering the bone of the eye socket).

According to veterinary surgical literature:

"The TE [third eyelid] is then reflected back to its normal position and the suture needle is passed back beneath the skin to engage the orbital periosteum a second time. The nylon is tied in a secure knot being careful not to place too much tension on the suture and restrict the movement of the third eyelid."

Post-Operative Care

Regardless of the technique used, post-operative care is critical to surgical success. Your dog must wear an Elizabethan collar (cone) at all times for 10 to 14 days to prevent them from rubbing or scratching at the delicate sutures. Your vet will prescribe topical antibiotic and anti-inflammatory eye drops, along with oral pain medications. You must restrict your dog's activity—no rough play, running, or heavy exercise—to prevent the sutures from tearing before the tissues have fully healed.

Prognosis

The prognosis for dogs undergoing surgical replacement of the third eyelid gland is excellent. When performed by an experienced veterinarian or a board-certified veterinary ophthalmologist, the success rate is high, and the vast majority of dogs go on to live comfortable lives with normal tear production.

However, owners must be prepared for the possibility of recurrence. Because the underlying tissue weakness is genetic, the surgical sutures can occasionally tear, allowing the gland to prolapse again. The recurrence rate is generally under 10% to 20%, but it can be higher in giant breeds or dogs with severe facial conformation issues. If a repair fails, a second surgery using a different technique or a combination of techniques is usually successful.

Prevention

Because cherry eye is caused by an inherited, structural weakness of the connective tissues, there is no lifestyle change, diet, or preventative care that can prevent it from occurring.

To reduce the prevalence of this condition in future generations, responsible breeding practices are essential. Dogs that develop cherry eye should not be bred, as they are highly likely to pass the genetic predisposition for weak third-eyelid connective tissues down to their offspring.

When to call your vet

If you notice a pink or red mass in the corner of your dog's eye, schedule an appointment with your veterinarian. While it is not a midnight emergency, the sooner the gland is surgically replaced, the less inflammation and permanent damage it will suffer.

You should seek immediate, same-day veterinary care if you notice any of the following emergency signs:

• Your dog is squinting, holding the eye tightly shut, or blinking excessively (indicates severe pain or a corneal ulcer).
• The discharge from the eye becomes thick, yellow, or green.
• The surface of the eye (cornea) appears cloudy, hazy, or bluish.
• Your dog is actively scratching or rubbing at their eye, which can cause rapid, severe self-trauma.

For specific breeds

If you own a Boston Terrier, English Cocker Spaniel, or English Bulldog, it is highly recommended to monitor their eyes closely during their first year of life.

In these predisposed breeds, cherry eye is frequently a bilateral condition, meaning it affects both eyes. If the gland prolapses in one eye, there is a very high likelihood (often exceeding 50%) that the other eye's gland will also prolapse within a few weeks or months. If your dog is diagnosed with cherry eye in one eye, your vet may discuss the possibility of monitoring the second eye closely, or even performing prophylactic pocket surgery on the unaffected eye if the tissue appears highly unstable, saving your dog from undergoing anesthesia twice.

Sources

• Fundamentals of Veterinary Ophthalmology, 3rd Edition, p. 293.
• Current Techniques in Small Animal Surgery, 5th Edition, pp. 183, 184, 186.