Can Worms Cause a Cat's Third Eyelid to Show?
The nictitating membrane, also known as the third eyelid, serves as a protective barrier for a cat's eye and is usually only partially visible during normal rest or sleep. When this third eyelid becomes persistently visible, it can be a sign of underlying health issues. One question pet owners often ask is whether worms can cause a cat's third eyelid to show. The answer is yes—under certain conditions, intestinal worms can indirectly lead to this startling symptom.
Understanding the Third Eyelid
A cat’s third eyelid is a thin, whitish membrane located in the corner of each eye. When visible, it may indicate:
- Discomfort
- Injury
- Neurological dysfunction
- Systemic illness
Its presence may be brief, such as during sleep or sedation, or prolonged, which typically signals a medical concern.
Haws Syndrome and Gastrointestinal Issues
Persistent third eyelid elevation is a hallmark of Haws syndrome, a benign and self-limiting condition often associated with gastrointestinal problems. One of the contributing factors to this syndrome is intestinal parasites like worms. When a cat is infested with worms, particularly tapeworms or roundworms, it may develop gastrointestinal inflammation, which can lead to the emergence of the third eyelid.
Haws syndrome usually affects both eyes and is more common in younger cats. The third eyelid visibility may appear suddenly and may not be accompanied by other severe ocular symptoms.
Signs of Worm Infestation
If worms are the underlying issue, cats may also exhibit:
- Vomiting
- Diarrhea
- Weight loss
- Increased appetite or lack of appetite
- Visible worms in stool or vomit
- Bloated abdomen
These signs, coupled with the showing of the third eyelid, suggest a systemic issue rather than an isolated eye problem.
Other Causes of Visible Third Eyelid
Although worms can be a cause, several other medical conditions may also result in third eyelid visibility, such as:
- Eye injuries or trauma
- Conjunctivitis
- Corneal ulcers
- Cherry eye (prolapsed gland)
- Horner’s syndrome, a neurological disorder
- Vestibular diseases
- Neurological tumors
Diagnosis and Treatment
Veterinarians will conduct a comprehensive exam that may include:
- Physical and neurological assessments
- Blood tests
- Fecal examination for parasites
- Eye examination with specialized tools
- Advanced imaging (X-rays, MRI)
Treatment depends on the underlying cause. If the third eyelid is caused by worms, the vet will prescribe deworming medication. Recovery is generally straightforward once the parasites are eradicated. In cases like Haws syndrome, no treatment may be necessary if the cat appears otherwise healthy and the issue resolves on its own in a few weeks.
Preventive Measures
To reduce the chances of third eyelid visibility due to worms or other causes:
- Ensure regular deworming (every 3 months or as recommended)
- Maintain good hygiene and a clean environment
- Provide high-quality, parasite-free food and clean water
- Conduct regular veterinary check-ups
- Monitor for any sudden behavioral or physical changes
When to Seek Veterinary Help
Contact your vet promptly if your cat shows:
- Both third eyelids persistently raised
- Ocular discharge, swelling, or redness
- Loss of appetite or weight
- Vomiting or diarrhea
- Nystagmus or head tilting
- Signs of disorientation or imbalance
Conclusion
The visibility of a cat’s third eyelid is often an early sign of health disturbances. While worms can indeed be a cause, particularly in cases linked to gastrointestinal upset like Haws syndrome, it is essential not to jump to conclusions. A professional diagnosis ensures the correct underlying cause is treated effectively. In many situations, early detection and treatment lead to a complete recovery and help prevent further complications.
