Why Are My Cat's Eyes Watery or Runny?

Common causes of eye discharge in cats, and what the colour and pattern can tell you.

Quick Answer

Clear, watery discharge is often linked to mild irritation or early-stage conjunctivitis.
Green or yellow discharge usually points to an infection that needs treatment.
One eye affected more than the other can suggest an injury, scratch, or foreign body.
A swollen, bulging, or very painful eye is an emergency and needs prompt veterinary care.

Common Causes of Watery or Runny Eyes in Cats

01 Conjunctivitis

Conjunctivitis is inflammation of the tissue around the eye and is one of the most common causes of eye discharge in cats. It can be linked to cat flu viruses, bacteria, or irritation, and often affects both eyes.

02 Allergies and Irritants

Dust, pollen, and strong household sprays can irritate a cat's eyes, leading to mild, clear watering that usually settles once the irritant is removed.

03 Blocked Tear Duct

If the duct that normally drains tears away becomes blocked or narrowed, tears can overflow down the face instead, causing persistent watering without other signs of irritation.

04 Scratch or Foreign Body One eye, sudden onset

A scratch to the surface of the eye, often from another cat during play or a fight, or a foreign body such as grass seed, typically causes sudden discomfort, squinting, and watering in one eye.

Sudden squinting or watering in just one eye, especially after a fight or time outdoors, is worth a vet check rather than waiting it out.

05 Eyelid Conformation

In some cats, particularly flat-faced breeds, the shape of the face or eyelids can mean tears don't drain as efficiently, leading to ongoing watering even without an active infection.

What the Discharge Can Tell You

Clear & Watery

Often mild irritation, allergy, or early conjunctivitis. Usually less urgent.

Yellow or Green

Usually suggests infection. Worth a vet appointment rather than waiting.

One Eye, Painful

Can suggest injury, scratch, or foreign body. See your vet promptly.

Contact Your Vet Immediately If

An eye looks swollen, bulging, or noticeably larger than the other
The eye is held tightly closed and your cat seems in significant pain
The cornea (the clear surface of the eye) looks cloudy or blue
There's been a known injury to the eye

Eye problems can worsen quickly, and prompt treatment gives the best chance of protecting your cat's sight.

When to Contact Your Vet

Discharge is yellow or green, or there's a noticeable amount of crusting
Your cat is squinting or holding one eye partly closed
The watering continues for more than a couple of days
Only one eye is affected

How Pet Med Direct Can Help

Pet Med Direct stocks gentle eye care wipes that can help keep the area around the eyes clean and comfortable for routine care.

If your vet diagnoses conjunctivitis, an infection, or another condition that needs eye drops or ointment, Pet Med Direct can help with prescription dispensing once your vet has issued a valid prescription.

Some treatments require a valid veterinary prescription. Pet Med Direct can only supply prescription medicines after the prescription has been checked. Always follow your vet's advice and the directions on the medicine label.

Frequently Asked Questions

Is it normal for cats to have a little eye discharge?

A very small amount of clear discharge, especially first thing in the morning, can be normal. Persistent, coloured, or thick discharge is not and is worth checking.

Can I clean my cat's eyes at home?

Gently wiping away mild discharge with a clean, damp cotton pad can help. Avoid using any human eye products, and see your vet if the discharge is coloured, persistent, or your cat seems uncomfortable.

Is cat flu the main cause of eye discharge?

It's a common cause, particularly when both eyes are affected alongside sneezing, but it isn't the only one. Allergies, scratches, and blocked tear ducts can all cause similar symptoms.

Why is only one of my cat's eyes affected?

This pattern often points to a localised cause, such as a scratch, foreign body, or injury, rather than a generalised infection or allergy.

Can flat-faced cats get watery eyes more often?

Yes, the shape of the face and eyelids in some breeds can make tear drainage less efficient, leading to more frequent watering even without an infection.

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This this article is for informational purposes only and does not constitute veterinary advice.
If you are concerned with your dog’s health, please consult a qualified veterinarian.