Feline Eye Discharge: Nine Prevalent Causes, Examined by Joanna Woodnutt, MRCVS and Reviewed by Catherine Barnette, DVM, Last Updated on August 28, 2025

Cats, much like humans, can experience eye discharge, which can be a sign of various health issues. It's essential to treat any eye discharge in cats as an urgent matter, as it may indicate an eye injury.

The most common cause of eye inflammation (conjunctivitis) in cats is an infection with feline herpesvirus type 1, often combined with other viral infections such as feline calicivirus, coronavirus, or bacterial agents. Environmental factors like drafts, pollen, or dust, and allergic reactions can also contribute.

Interestingly, a study found that flat-faced cat breeds, such as Persians and Exotic Shorthairs, are more prone to eye discharge due to their facial conformation. This is because their squashed noses can compress their tear ducts, making them more susceptible to conditions like entropion, where the eyelid rolls inward, causing irritation to the eye surface.

Entropion was found in 32% of the cats in the study, and it's a condition that can cause eye discharge due to the irritation of the eye surface.

Airborne irritants are more likely if your cat spends a lot of time indoors, so it's important to check your cleaning materials carefully and avoid using anything too strong. Allergies and airborne irritants can cause watery eyes in cats, similar to how our eyes water during hay fever.

Foreign bodies such as another cat's claw can cause pain and excessive blinking in cats, leading to watery discharge. Dental disease, especially a tooth root abscess, can also cause eye discharge by compressing the tear duct.

Feline upper respiratory infections, also known as 'cat flu', are a common cause of eye discharge. Uveitis, an inflammation of a particular part of the eye, can also cause eye discharge and is usually caused by an infection.

Regularly brushing your cat's teeth and inspecting their mouth for bad smells or tooth damage can help prevent dental disease. Proper vaccination, including the FVRCP vaccine, can help protect against cat flu, one of the leading causes of eye discharge in cats.

It's important to note that cat eye discharge can vary in colour and thickness. Watery discharge is usually clear, while discharge from an infection is often yellow or green and sticky. Vets should assess eye discharge related to dental disease as it's very painful. Blocked tear ducts can also cause eye discharge due to a failure of normal tears to drain properly.

In conclusion, cat eye discharge is a common condition that can be caused by increased tear production, blockage in the drainage route, or an eye infection. As a cat owner, it's essential to monitor your cat's eye health and seek veterinary advice if you notice any unusual discharge.

Feline Eye Discharge: Nine Prevalent Causes, Examined by Joanna Woodnutt, MRCVS and Reviewed by Catherine Barnette, DVM, Last Updated on August 28, 2025