That red mass in the corner of your dog’s eye is not just cosmetic. It is a sign that something has slipped out of place, and it needs attention.
Cherry eye is one of those conditions that looks alarming precisely because it appears suddenly and visibly. One day, the eye looks normal. Next, there is a round, fleshy, red or pink mass sitting in the inner corner of the eye. It is not a growth. It is not a tumour. It is the gland of the third eyelid, a structure that is supposed to stay tucked out of sight, that has prolapsed forward and is now exposed.
The good news is that cherry eye is treatable. The important news is that leaving it untreated causes progressive damage that becomes harder to manage with time.
What Is Cherry Eye in Dogs?
Dogs, unlike humans, have three eyelids. The third eyelid, also called the nictitating membrane, sits in the inner corner of the eye and provides an additional layer of protection for the corneal surface. Attached to the base of this third eyelid is a tear-producing gland, known as the nictitans gland or third eyelid gland, which contributes approximately forty per cent of the eye’s total tear production.
This gland is normally held in position by a small ligament anchoring it to the connective tissue at the base of the third eyelid. When that ligament is weak or fails, the gland loses its anchorage, flips forward, and prolapses over the edge of the third eyelid. The exposed gland appears as the characteristic red or pink fleshy mass visible in the inner corner of the eye that gives the condition its common name.
Because this gland is responsible for a significant proportion of the eye’s tear film, its prolapse and the damage that accumulates from ongoing exposure directly threaten the eye’s ability to keep itself adequately lubricated.
Symptoms of Cherry Eye in Dogs
The symptoms of cherry eye are usually visible from the first moment the gland prolapses.
A red or pink rounded mass in the inner corner of one or both eyes is the defining sign. It may be small and partially visible, or it may be large enough to cover a significant portion of the visible eye surface.
Eye discharge accumulates as the prolapsed gland and the exposed inner eyelid surface produce excess mucus in response to irritation.
Rubbing and scratching at the eye reflects the discomfort caused by the exposed, inflamed gland tissue and the surface irritation it creates.
Swelling and redness of the tissues surrounding the prolapsed gland develop as the condition persists and inflammation increases.
Dryness and surface changes develop in chronic or untreated cases, as the compromised tear gland function begins to reduce the overall tear film quality and volume, leaving the corneal surface inadequately protected.
Causes of Cherry Eye in Dogs
Weak Connective Tissue
The primary cause of cherry eye is a structural weakness in the connective tissue ligament that normally anchors the third eyelid gland in its correct position. When this ligament is insufficiently strong to maintain the gland’s position under the normal mechanical stresses of eye movement and blinking, the gland slips out of place.
This connective tissue weakness is largely genetic in origin, which explains why cherry eye is so strongly associated with specific breeds and tends to run in family lines.
Genetic Predisposition
The inherited tendency toward weak periorbital connective tissue means that cherry eye is significantly more common in certain breeds. It is not caused by anything the dog has been exposed to or experienced. It is a structural predisposition that was present from birth.
Trauma and Inflammation
In some cases, direct trauma to the area of the third eyelid or significant inflammation around the eye can displace the gland from its normal position even in dogs that do not carry a strong genetic predisposition. These cases are less common than the primary genetic form but represent a recognised secondary pathway to gland prolapse.
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Breeds at Higher Risk
Cherry eye is seen predominantly in brachycephalic breeds and certain other breeds with anatomical features that place increased mechanical stress on the periorbital connective tissue.
Breeds commonly affected include the English Bulldog, French Bulldog, Pug, Shih Tzu, Cocker Spaniel, Beagle, Basset Hound, Lhasa Apso, and Boston Terrier. In these breeds, cherry eye can appear as early as a few months of age, and bilateral involvement, where both eyes are eventually affected, is common. An owner who notices cherry eye in one eye of a predisposed breed should be aware that the other eye carries a significant risk of developing the same condition.
How Cherry Eye Develops
Understanding the sequence of events helps explain why prompt treatment matters.
The third eyelid gland sits anchored in position, invisible to the owner and doing its job of contributing to tear production quietly and consistently. When the anchoring ligament weakens, the gland begins to lose its stable position. Minor movements, eye rubbing, or simply the mechanical stress of normal blinking can be sufficient to flip the gland forward over the edge of the third eyelid.
Once prolapsed and exposed, the gland is no longer in the protected environment it was designed to occupy. It is now exposed to air, to the mechanical friction of blinking, and to environmental debris. The exposed glandular tissue becomes inflamed. The inflammation further compromises the gland’s ability to produce tears effectively. If the gland remains prolapsed for an extended period, the chronic inflammation causes progressive damage to the glandular tissue itself, making successful surgical repositioning more difficult and reducing the gland’s functional capacity even after correction.
This progression from a recently prolapsed, still-healthy gland to a chronically inflamed and damaged one is the reason early treatment consistently produces better outcomes than delayed management.
Diagnosis of Cherry Eye in Dogs
Diagnosis of cherry eye is primarily visual. The prolapsed gland is almost always immediately apparent on examination, and the characteristic appearance of a red fleshy mass in the inner corner of the eye is highly recognisable.
The veterinary examination extends beyond confirming the visible diagnosis to assessing the health of the eye surface and the degree of glandular and conjunctival inflammation present.
The Schirmer tear test measures tear production and provides a baseline assessment of how much the prolapse has already affected the tear film. This baseline is important both for guiding treatment decisions and for monitoring the eye after surgical correction.
Fluorescein staining of the cornea identifies any surface ulceration that may have developed secondary to the exposure and irritation created by the prolapsed gland.
Treatment of Cherry Eye in Dogs
Medical Management
Topical anti-inflammatory eye drops and lubricating solutions may be prescribed to reduce inflammation and protect the corneal surface while treatment planning is underway. These measures provide temporary relief and help limit the damage to the prolapsed gland tissue, but do not address the underlying displacement. Medical management alone is not a definitive treatment for cherry eye.
Surgical Repositioning
Surgery is the definitive and gold-standard treatment for cherry eye. The goal of surgery is to reposition the prolapsed gland back into its correct anatomical position and secure it there, restoring the gland’s normal function and protecting it from further prolapse.
The preferred surgical technique involves creating a pocket in the tissue of the third eyelid and tucking the gland back into place, then suturing the pocket closed to maintain the gland in its correct position. This approach preserves the gland and its tear-producing function.
The surgical approach contrasts with an older technique of simply removing the prolapsed gland entirely. Removal was once commonly performed but is now recognised as inappropriate for most cases because it eliminates a structure responsible for approximately forty per cent of the eye’s tear production. Dogs that have had their third eyelid gland removed carry a significantly elevated lifetime risk of developing keratoconjunctivitis sicca, commonly known as dry eye, a chronic condition requiring lifelong management.
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Why Surgery Is the Preferred Approach
The decision to reposition rather than remove the gland is grounded in one straightforward fact: the gland matters. Forty per cent of the eye’s total tear film comes from this structure. Removing it to resolve a visible problem creates an invisible but progressive problem that affects the dog for the rest of its life.
Dry eye resulting from inadequate tear production causes chronic corneal irritation, recurrent infections, progressive corneal scarring, and ultimately significant visual impairment. It requires daily topical treatment to manage, and it is never fully cured once established. Preventing it by preserving the tear gland through surgical repositioning is always the more responsible and clinically appropriate choice when repositioning is technically feasible.
Conditions that affect tear film quality and ocular surface health from other angles, such as hypothyroidism in dogs, which can reduce tear production independently, illustrate why preserving every component of the tear-producing system is important in dogs already predisposed to ocular surface complications.
Prognosis and Recovery
The prognosis for dogs treated surgically for cherry eye is generally good. Successful repositioning of the gland in an early and minimally inflamed case carries a high success rate, with the gland returning to normal function and the visible mass resolving.
Recurrence after surgical repositioning is possible, particularly in breeds with strong genetic predispositions to connective tissue weakness. Some dogs require a second surgical procedure. The risk of recurrence is higher when surgery is delayed, as chronic inflammation damages the tissue that the surgeon needs to work with.
Recovery following surgery involves a period of restricted activity, an Elizabethan collar to prevent rubbing, and topical treatment as prescribed by the veterinarian. Most dogs recover comfortably and without complications when post-operative care is followed consistently.
Complications If Left Untreated
Cherry eye that is left without treatment causes a progressive sequence of complications that significantly worsen the dog’s situation.
Chronic irritation and conjunctivitis develop as the exposed, inflamed gland tissue continues to create mechanical and inflammatory irritation of the eye surface.
Secondary bacterial infection is common in chronically prolapsed glands, as the inflamed and exposed tissue provides an environment susceptible to bacterial colonisation.
Dry eye (keratoconjunctivitis sicca) develops when prolonged exposure and inflammation damage the gland’s functional tissue to the point where tear production is permanently reduced. This is the most significant long-term complication of untreated cherry eye and requires lifelong management.
Severe allergic or inflammatory responses affecting the eye and periorbital tissues, such as those seen in anaphylaxis in dogs, can exacerbate existing eye conditions, including cherry eye, by increasing local inflammatory burden and placing additional stress on already compromised ocular tissues.
The broader context of diseases of the orbit of the eye in dogs provides useful clinical background on how the structural and supporting tissues of the eye can be involved in a range of conditions that share the common feature of disrupting the normal anatomy and protection of the ocular surface.
Cherry Eye Versus Other Eye Conditions
Cherry eye is sometimes confused with other eye conditions because of its visible and dramatic appearance. Understanding what distinguishes it from similar-looking presentations prevents mismanagement.
Cherry eye is a prolapsed gland. The visible mass is soft, red or pink, sits specifically in the inner corner of the eye, and is a displaced anatomical structure rather than a new growth or infection.
Conjunctivitis involves diffuse redness and inflammation of the conjunctival surface without a distinct prolapsed mass. It does not produce the characteristic rounded bulge of cherry eye.
Proptosis is a displacement of the entire eyeball forward out of its socket, which is a traumatic emergency. It is dramatically different in presentation, involving the whole eye rather than a localised mass in the inner corner.
When to See a Vet
Any dog showing a visible red or pink mass in the inner corner of one or both eyes should be seen by a veterinarian promptly. Cherry eye is not an emergency in the way that proptosis or a corneal ulcer is, but it is not a condition to observe and hope resolves on its own either.
The prolapsed gland will not return to its correct position spontaneously in the vast majority of cases. Every day it remains exposed is another day of accumulating inflammation and damage to the glandular tissue. The sooner a veterinary assessment is arranged and surgical correction is planned, the better the outcome for the gland’s function and the eye’s long-term health.
