Haws Syndrome is the term used to describe the bilateral protrusion of a cat’s third eyelids, also known as the nictitating membranes. When owners notice the whitish or pink membranes partially covering both eyes, it often causes immediate alarm. While the condition is not painful and does not damage the eye itself, it raises a concern about the cat’s overall health.
Understanding the Visible Symptom
The third eyelid is a natural, protective structure usually tucked away in the inner corner of a cat’s eye, only briefly visible when blinking or in deep sleep. In Haws Syndrome, this thin membrane becomes permanently elevated and visible across both eyes simultaneously, appearing as a white or pale pink sheet partially obscuring the eye surface. This protrusion is generally not due to an infection or primary ocular disease, and the eyes themselves are typically otherwise normal.
The appearance is caused by a temporary dysfunction in the sympathetic nervous system, which normally controls the retraction of the third eyelid. This nerve imbalance allows the membrane to stay elevated, which can temporarily obstruct the cat’s field of vision.
Addressing the Danger: Underlying Causes
Haws Syndrome itself is considered benign and is a self-limiting condition, meaning it usually resolves without specific treatment. However, the condition acts as a red flag, indicating a systemic upset within the cat’s body that may pose a risk to its health. The danger is not the protruding eyelid but the underlying cause that triggered the nerve dysfunction.
This syndrome is strongly associated with gastrointestinal disturbances, particularly diarrhea. Underlying issues often include internal parasites, such as tapeworms, or viral and bacterial infections affecting the digestive tract. It is hypothesized that the gut disturbance affects the autonomic nervous system, leading to the third eyelid protrusion. Severe and prolonged gastrointestinal issues can lead to dehydration or nutrient loss, which are the real threats to the cat’s well-being.
Necessary Steps for Resolution
Because Haws Syndrome is a symptom of a systemic issue, a veterinary visit is necessary to identify and treat the root cause. Diagnosis involves a full physical and ocular examination to rule out other serious eye conditions that mimic the symptom. The veterinarian will also perform a fecal sample analysis to check for common culprits like intestinal parasites, which are frequently linked to the syndrome.
Treatment focuses on resolving the underlying systemic problem, not the eyelid itself. This might involve deworming medication or supportive care like a bland diet or probiotics to manage diarrhea. Once the primary issue is successfully treated, the third eyelids should gradually retract to their normal position, typically resolving within four to eight weeks.