Understanding and Managing Haws Syndrome in Cats
Haws syndrome is a relatively benign and self-limiting condition observed in cats, characterized by the symmetrical protrusion of the third eyelid in both eyes, without any apparent primary ocular disease. Although it may appear alarming to pet owners, Haws syndrome typically does not pose a serious health threat and often resolves without treatment.
What Is the Third Eyelid?
The third eyelid—also known as the nictitating membrane—is a protective structure located at the inner corner of the eye. Its main functions are:
- Protecting the eye from trauma and foreign objects
- Distributing tear film to lubricate the eye surface
- Acting as a barrier against potential infections
Normally, this membrane remains tucked away and is barely visible. Its involuntary elevation can be triggered by specific conditions, one of which is Haws syndrome.
What Causes Haws Syndrome?
The precise cause of Haws syndrome is not fully understood, but it is commonly linked to gastrointestinal upset or inflammation. Unlike other eye conditions, it is not related to direct trauma, infections, or allergies affecting the eye itself.
Known associations include:
- Mild GI disturbances like diarrhea or intestinal inflammation
- Recovery from viral or bacterial infections
- Possible link to parasites such as tapeworms or roundworms
Clinical Signs of Haws Syndrome
The hallmark sign of Haws syndrome is:
- Bilateral (both eyes) elevation of the third eyelid
These changes occur without accompanying redness, swelling, discharge, or squinting commonly seen in infectious or traumatic eye conditions. Cats typically appear otherwise healthy, although some may have mild digestive symptoms.
Diagnosis
A veterinarian will perform a comprehensive eye examination to rule out other causes of third eyelid protrusion. Tests may include:
- Ophthalmoscopy to assess the eye structure
- Fluorescein staining to rule out corneal ulcers
- Intraocular pressure testing
- Phenylephrine eye drop test (may temporarily retract the third eyelid in Haws syndrome)
- Blood, fecal, or urine tests to detect systemic or parasitic infections
A confirmed diagnosis of Haws syndrome is often one of exclusion, made after ruling out other potential issues.
Treatment Options
Treatment is rarely necessary for Haws syndrome itself. In most cases, the condition resolves spontaneously over a period of days to weeks. However, supportive care may be offered in certain cases:
- Treat underlying GI issues if present, using veterinarian-prescribed medications or dietary changes
- Deworming protocols to address suspected parasitic infections
- Hydration support in cases of dehydration from diarrhea or vomiting
Owners should refrain from using any over-the-counter eye drops or medications meant for humans, as these can be harmful to cats.
When to Seek Veterinary Care
Although Haws syndrome is benign, persistent elevation of the third eyelid should not be ignored. Contact a veterinarian if you observe:
- Symptoms lasting longer than 2–3 weeks
- Discharge, redness, or swelling of the eye
- Behavioral changes indicating pain or discomfort
- Digestion issues that worsen or don’t improve
Differentiating Haws Syndrome from Other Conditions
Other causes of third eyelid protrusion include:
- Horner’s syndrome: Includes constricted pupil, drooping upper eyelid, and retracted eyeball on one side
- Infectious conjunctivitis: Often presents with eye discharge, redness, and squinting
- Cherry eye: Prolapse of the third eyelid gland, visible as a pink mass
- Eye trauma or corneal ulcers
- Neurological disorders or systemic illness
Veterinary evaluation is vital to distinguish between these conditions.
Prognosis
The prognosis for Haws syndrome is excellent. The condition is temporary, and the third eyelid usually returns to its normal position without incident. In rare cases where it persists or recurs, a deeper investigation into potential gastrointestinal or neurological causes may be required.
Preventive Tips for Eye Health
Although Haws syndrome itself cannot be directly prevented, overall eye and health maintenance in cats can reduce the risk of similar issues:
- Keep vaccinations up to date
- Conduct regular eye checks at home
- Schedule routine vet visits
- Keep your cat indoors to minimize exposure to parasites and trauma
- Practice good hygiene, especially in multi-cat households
Conclusion
Haws syndrome in cats is alarming in appearance but generally harmless and self-limiting. Understanding the condition helps pet owners identify it early and avoid unnecessary worry. Despite its fleeting nature, any unusual eye changes should prompt a vet consultation to rule out underlying issues that require treatment.
