Symptoms of Canine Third Eyelid Prolapse

Canine third eyelid prolapse, also known as “cherry eye,” is a relatively common condition affecting dogs. While the exact cause remains undetermined, several factors are implicated in its development. These include irritation from hair around the eye, excessive glandular secretions, congenital defects in the nictitating membrane cartilage and tissues, and even genetic predisposition. Understanding the symptoms is crucial for early diagnosis and appropriate treatment.

Early Stage Symptoms:

The initial symptoms often manifest as inflammation and swelling of the third eyelid due to infection. The conjunctiva (the membrane lining the eyelid and covering the white of the eye) becomes reddened (conjunctivitis), and excessive tearing (epiphora) is observed. This excessive tearing frequently wets the fur beneath the eye. A small, pinkish, fleshy mass—often described as a “cherry”—begins to protrude from the inner corner of the lower eyelid. In many cases, this affects one eye initially, but the other eye may become affected within a short period (3-7 days). Sometimes, both eyes are affected simultaneously. The size of the prolapsed mass typically increases rapidly, often reaching the size of a pea within a week.

These early stages are accompanied by noticeable inflammation and discomfort, leading to increased eye discharge, initially watery or serous, that can gradually become thicker and mucopurulent. The affected dog often exhibits signs of eye irritation, such as frequent pawing or rubbing of the affected eye. This constant irritation can lead to further complications, including corneal abrasions or exacerbated eye inflammation.

Late Stage Symptoms:

As the condition progresses, the discharge becomes increasingly purulent (pus-like). While antibiotic eye drops might temporarily alleviate the inflammation, they do not address the underlying problem. The inflammation tends to recur after a few days, indicating the need for a more definitive treatment. In severe cases, the prolapsed mass may become dark red and even ulcerate. If left untreated, this can result in more serious secondary complications like keratitis (inflammation of the cornea), corneal ulcers, or even perforation, potentially leading to blindness. The chronic irritation can also damage the cornea, causing scarring and impairing vision.

Differentiating Prolapse from Other Conditions:

It’s important to differentiate third eyelid prolapse from other eye conditions that might present similar symptoms. For example, a conjunctival cyst might appear similar, but it’s typically a fluid-filled sac rather than a prolapsed gland. Similarly, tumors or other masses in the eye area need to be ruled out through proper veterinary examination.

Breed Predisposition:

Certain breeds seem to be predisposed to third eyelid prolapse. Brachycephalic breeds (those with short noses), such as Pugs, Pekingese, and Shih Tzus, are frequently affected, due in part to the anatomical structure of their eyes and the potential for increased pressure within the orbit. Other breeds with a higher incidence include Cocker Spaniels, Bulldogs, and Shar-Peis. Age is also a factor, with young dogs (2-16 months old) often being more susceptible.

Potential Underlying Causes:

While the exact etiology remains elusive, several factors contribute to the development of third eyelid prolapse. These include:

Congenital Factors: Genetic predisposition plays a significant role. Defects in the attachment of the gland to the surrounding tissues, underdeveloped connective tissue, or abnormal development of the gland itself can all contribute.

Infections: Infections, such as conjunctivitis, can cause inflammation and swelling of the third eyelid, leading to prolapse.

Trauma: Physical trauma or injury to the eye area can disrupt the tissues supporting the third eyelid, potentially causing it to prolapse.

Immune-Mediated Diseases: In some cases, autoimmune diseases might trigger inflammation and contribute to the condition.

Environmental Factors: While not a primary cause, environmental irritants like dust or pollen can exacerbate existing inflammation or predisposition.

Conclusion:

Canine third eyelid prolapse is a concerning condition requiring prompt veterinary attention. Early recognition of the symptoms, from initial redness and swelling to the appearance of the characteristic prolapsed mass, is critical. While topical medications may offer temporary relief in mild cases, surgical intervention is often necessary for a permanent solution. Regular veterinary check-ups, especially for breeds prone to this condition, can help in early detection and prevent the development of more serious complications. Do not attempt to treat this at home without consulting a veterinarian; prompt professional care is vital to protect your dog’s eyesight and overall well-being.