Can stress cause a cat's third eyelid to show?

Understanding Third Eyelid Protrusion in Cats: Causes and Care

Cats possess a unique protective structure in their eyes known as the third eyelid, or nictitating membrane. This thin film of tissue, typically hidden from view, resides in the inner corner of the eye and serves multiple vital functions: Main Functions:

• Protecting the eye from injuries and foreign bodies
• Distributing tear film to lubricate the eye’s surface
• Shielding the eye during sleep or sedation

In healthy cats, the third eyelid is barely noticeable. However, when it becomes prominently visible or protruded, it signals an underlying issue that may require veterinary attention.

Common Causes of Third Eyelid Elevation

Third eyelid visibility is **not normal** when persistent and can be attributed to several factors:

1. Sleep or Sedation: Temporary elevation is typical during rest or recovery from anesthesia.
2. Eye Injury or Irritation: Scratches, ulcers, conjunctivitis, and foreign bodies can all stimulate third eyelid movement.
3. Infections: Viral or bacterial infections, especially those associated with upper respiratory issues, often cause eye inflammation and membrane projection.
4. Haws Syndrome: A symmetrical protrusion of both third eyelids, often linked to mild gastrointestinal distress with no primary eye disease. It usually resolves on its own.
5. Horner’s Syndrome: A neurological disorder presenting with a retracted eyeball, constricted pupil, drooping eyelid, and the third eyelid being more noticeable on the affected side.
6. Cherry Eye: A prolapsed gland of the third eyelid seen as a pink mass, requiring surgical correction.
7. Systemic Illness: Dehydration, fever, or dramatic weight loss may trigger third eyelid appearance.
8. Allergic Responses: Exposure to allergens or irritants may cause ocular swelling and membrane protrusion.
9. Nerve Damage: Trauma or infections affecting facial or neck nerves can alter eyelid function.

Can Stress Be a Factor?

While stress is not a direct cause of third eyelid protrusion, it can contribute indirectly. Stress may exacerbate or lead to conditions like gastrointestinal upset, particularly in cases such as Haws syndrome. This syndrome is sometimes triggered by systemic imbalance possibly associated with stress, malnutrition, or mild intestinal infections.

Associated Clinical Signs

If your cat exhibits a visible third eyelid, it may be accompanied by additional symptoms:

• Increased tearing (epiphora)
• Eye discharge (clear, yellow, or green)
• Redness and swelling around the eyes
• Squinting or blinking excessively
• Sunken or protruding eyeball
• Behavioral changes, like eye rubbing or pawing

Diagnostic Approach

Veterinarians use several tools to diagnose the cause of third eyelid protrusion:

• General physical and ophthalmic exams
• Fluorescein stain tests to detect corneal damage
• Tear production and pressure measurements
• Phenylephrine challenge for suspected Haws or Horner’s syndrome
• Blood and urine tests for systemic illnesses
• Imaging studies for neurological or structural abnormalities

Treatment Options

Management varies based on diagnosis:

• Temporary causes such as sleep or mild stress require no intervention
• Infections or injuries: Treated with topical or oral antibiotics, antivirals, or anti-inflammatory drugs
• Cherry eye: Requires surgical repositioning to avoid chronic dry eye
• Neurological conditions: May resolve spontaneously or need targeted treatment
• Allergic reactions: Managed by identifying and eliminating the allergen, plus supportive medications

Conjunctivitis and Third Eyelid Involvement

Conjunctivitis, or inflammation of the eye's outer membrane, is a common reason for third eyelid elevation. In cats, it may originate from:

• Feline herpesvirus
• Calicivirus
• Chlamydophila felis
• Mycoplasma
• Non-infectious irritants or allergens

Home Care and Veterinary Advice

While only a vet can accurately diagnose and treat third eyelid elevation, owners can provide supportive care:

• Clean discharge gently with a moistened cotton ball
• Avoid human eye drops
• Seek prompt veterinary care for persistent or worsening symptoms

Preventive Measures

Keep your cat’s eyes healthy with these practices:

• Perform routine eye inspections
• Visit a vet regularly
• Ensure a clean, irritation-free environment
• Trim nails to avoid eye injuries
• Limit stressful situations
• Keep cats indoors to avoid trauma and infections
• Quarantine new cats before introduction

Conclusion

A visible third eyelid in cats warrants attention. While temporary in some cases, persistent or recurring protrusion reflects underlying issues, from infections and injuries to nerve or systemic disorders. Stress may play a role indirectly, particularly in syndromes involving the gastrointestinal system. Timely diagnosis and appropriate care are essential to maintaining your cat’s eye health and comfort.