Why doesn't the cat's third eyelid close? - briefly
The third eyelid in cats, also known as the nictitating membrane, may not close due to various reasons, such as irritation, infection, or trauma to the eye. This condition, often referred to as "cherry eye" or prolapse of the gland of the third eyelid, requires veterinary attention to determine the underlying cause and appropriate treatment.
Why doesn't the cat's third eyelid close? - in detail
The third eyelid in cats, also known as the nictitating membrane or haw, is a thin, transparent or translucent piece of tissue that moves horizontally across the eye. It serves several important functions, including protecting the eye from debris, maintaining moisture, and providing additional coverage in certain situations. However, there are instances when the third eyelid does not close properly, which can be indicative of underlying health issues.
One common reason for the third eyelid to remain partially or fully exposed is a condition known as "cherry eye." This occurs when the gland associated with the third eyelid prolapses, or pops out of its normal position. Cherry eye is more commonly seen in certain breeds, such as Bulldogs and Beagles, but it can affect any cat. The prolapsed gland appears as a red, fleshy mass in the corner of the eye, and it can cause irritation and discomfort. Veterinary intervention is typically required to correct this condition, often involving surgical repositioning of the gland.
Infections and inflammation of the eye or surrounding tissues can also cause the third eyelid to remain visible. Conditions such as conjunctivitis, corneal ulcers, or other ocular infections can lead to swelling and irritation, making it difficult for the third eyelid to retract properly. These conditions often present with additional symptoms, such as redness, discharge, and squinting. Prompt veterinary care is essential to address the underlying infection and alleviate symptoms.
Trauma to the eye or surrounding area can result in damage to the muscles and tissues that control the third eyelid. Injuries from fights, accidents, or foreign objects can lead to swelling, bruising, and impaired function of the eyelid. In severe cases, surgical repair may be necessary to restore proper function.
Diseases affecting the nervous system, such as Horner's syndrome, can also cause the third eyelid to remain partially or fully exposed. Horner's syndrome is characterized by the constriction of the pupil, drooping of the upper eyelid, and protrusion of the third eyelid. This condition typically results from damage to the sympathetic nerves that supply the eye and surrounding structures. Underlying causes of Horner's syndrome can include tumors, injuries, or other neurological disorders, and a thorough veterinary evaluation is necessary to determine the root cause and appropriate treatment.
In some cases, the third eyelid may remain visible due to anatomical abnormalities or congenital defects. Certain breeds or individual cats may have a naturally more prominent third eyelid, which can give the appearance of it being partially exposed. While this may not always indicate a health issue, it is important to monitor for any changes or additional symptoms that could suggest an underlying problem.
Regular veterinary check-ups and prompt attention to any changes in the appearance or behavior of the third eyelid are crucial for maintaining ocular health in cats. Early detection and treatment of any issues can prevent further complications and ensure the overall well-being of the animal. If the third eyelid remains visible for an extended period or is accompanied by other concerning symptoms, it is advisable to consult with a veterinarian for a comprehensive evaluation and appropriate care.