protrusion of the third eyelid in dogs

Protrusion of Third Eyelid in Dogs

Overview of Third Eyelid Protrusion in Dogs

Protrusion, prolapse, or elevation of the third eyelid refers to the abnormal elevation of the smooth inner eyelid that is located between the cornea and the inside corner of the eyelids closest to the nose. The third eyelid (TE) is usually retracted beneath the dog’s eyelids and barely noticeable. The third eyelid is also sometimes called the membrana nictitans or nictitating membrane.

Numerous disorders affecting the eye, TE and soft tissues behind the eye can result in TE protrusion. Therefore, TE protrusion represents a common yet nonspecific symptom of ophthalmic disease that warrants further diagnostic evaluation.

The causes of protrusion of the TE fall into one of several categories:

What to Watch For

Diagnosis of Third Eyelid Protrusion in Dogs

Diagnostic tests may include one or more of the following:

Treatment of Third Eyelid Protrusion in Dogs

Successful treatment relies solely upon obtaining an accurate diagnosis.
No symptomatic therapy can be initiated until the precise cause of TE elevation is identified.

Home Care for Dogs with Third Eyelid Protrusion

Vision is not usually compromised unless the third eyelid covers more than 1/2 of the eye. The underlying cause of the prolapse may affect vision, however. Confine your pet to a safe area until the cause of the problem is determined.

Do not administer human over-the-counter medications, such as Visine® or other ophthalmic remedies intended to “reduce eye redness” or irritation, because these medications rarely help the problem and may make diagnosis of the cause more difficult.

Information In-depth on Canine Third Eyelid Protrusion

Elevation, prolapse or protrusion of the third eyelid (membrana nictitans, nictitating membrane) refers to the abnormal elevation of the smooth inner eyelid that is located between the cornea and the inside corner of the eyelids closest to the nose. The third eyelid (TE) is usually retracted beneath the eyelids and barely noticeable. The ability to move the TE is involuntary in most animals, with the exception of birds and most reptiles.

Causes of Canine Third Eyelid Protrusion

Numerous disorders affecting the eye, the tissues in the orbit behind the eye, and the neurologic functions around the eye can result in TE protrusion. In addition, certain systemic diseases and medications can also cause this condition. Therefore, TE protrusion in an animal represents a nonspecific symptom that warrants further diagnostic evaluation by a veterinarian to determine its exact cause.

Neurologic causes of prolapse of the third eyelid include the following:

Diagnosis In-depth for Canine Third Eyelid Protrusions

Diagnostic tests may include one or more of the following:

Treatment In-depth for Dogs with Third Eyelid Protrusion

In dogs with one pigmented and one nonpigmented TE, an optical illusion makes the nonpigmented TE appear protruded or “elevated.” No problems result from this lack of pigmentation and no treatments are necessary.
Ultimate therapy of TE protrusion depends on identifying the exact cause of the problem. There are numerous possible causes for TE elevation; therefore, it is essential to pinpoint a specific cause to provide appropriate treatment.Do not administer human over-the-counter medications, such as Visine® or other ophthalmic remedies intended to “reduce eye redness” or irritation, because these medications rarely help the problem and may make diagnosis of the cause more difficult.