By Dial A Vet Veterinary Team
Cats are good at hiding discomfort, so a watery eye is often one of the first visible clues that something is wrong. A Persian with tear-stained cheeks every day, a kitten with crusty, half-closed eyes and sneezing, and an adult cat that suddenly squints in one eye are three very different situations. Many causes respond well to treatment, but some, such as corneal ulcers, can deepen quickly if they are left.
Key takeaways
- Feline herpesvirus, part of the cat flu complex, is the most common cause of watery, inflamed eyes in cats.
- Flat-faced breeds such as Persians, Himalayans and Exotic Shorthairs often have constant tear overflow because of their face shape.
- Squinting, a cloudy patch on the eye or holding the eye shut needs a vet the same day.
- Herpesvirus flare-ups can come back during stress, such as moving house or boarding.
- Never use human eye drops or leftover medicines in a cat's eyes.
What the tears look like
- Clear and watery: irritation, early viral infection, a blocked tear duct or a flat face.
- Thick, yellow or green: bacterial infection, often on top of a viral one.
- Brown or rust staining at the inner corner: chronic overflow, common in flat-faced breeds.
- Third eyelid showing: the pale membrane across the inner corner can rise when the eye is sore or the cat is unwell.
Common causes
Cat flu and conjunctivitis
Feline herpesvirus type 1 and feline calicivirus cause most cat flu. Herpesvirus in particular targets the eyes, causing conjunctivitis and sometimes corneal ulcers. Cats often sneeze and have a runny nose too. After infection, many cats carry herpesvirus for life, and stress can trigger flare-ups. See our articles on cat flu and conjunctivitis in cats.
Chlamydia felis is another cause of conjunctivitis, especially in young cats from multi-cat households. It often starts in one eye and spreads to the other.
Face shape and tear drainage
In flat-faced breeds, the tear duct openings can be kinked or poorly positioned, and the eyes are prominent. Tears spill onto the face instead of draining to the nose. Some of these cats also have inward-rolling lower eyelids, which rub the cornea.
Corneal ulcers and injuries
A scratch from another cat, a plant or rough play can damage the cornea. Herpesvirus can also cause ulcers. Ulcers are painful and usually cause squinting.
Foreign bodies
Grass seeds, dust or litter particles can lodge under the eyelids. Usually only one eye is affected, and the cat may paw at it.
Allergies and irritants
Less common in cats than in dogs, but smoke, strong cleaning products and some litters can irritate the eyes.
Other causes
Inflammation inside the eye (uveitis), glaucoma and eyelid tumours, including squamous cell carcinoma in white cats with sun exposure, are less common but more serious.
When to see a vet
Same day: squinting, an eye held shut, a cloudy or white patch on the eye, an eye that looks different in size or colour, an injury, or a kitten with crusted, sealed eyes or one that is not eating.
Within a day or two: yellow or green discharge, watery eyes with sneezing, or a third eyelid that stays raised.
Routine check: long-standing tear staining in a flat-faced cat with otherwise comfortable eyes.
How vets find the cause
Your vet will examine the eyes, eyelids and third eyelids, and look at the nose and mouth for other cat flu signs. A fluorescein stain shows up ulcers. Swabs may be taken to test for herpesvirus, calicivirus or chlamydia. Tear duct flushing and eye pressure checks may be needed.
Treatment depends on the cause and may include medicated eye drops or ointment, antiviral treatment for herpesvirus in some cases, supportive care for cat flu, or surgery for eyelid problems. Your vet will tailor the plan to your cat.
Caring for a cat with watery eyes
- Wipe tears and crust gently with a soft pad moistened with sterile saline or cooled boiled water. Use a fresh pad for each eye.
- Keep food tempting and warm. Cats with blocked noses lose their sense of smell and may stop eating.
- Reduce stress where possible, especially in cats with known herpesvirus.
- Keep sick cats separate from other cats and wash hands between them.
- Make sure vaccinations are current. Core vaccines protect against herpesvirus and calicivirus.
What not to do
- Do not use human eye drops, tea bags or herbal eyewashes.
- Do not use essential oils near cats. Many are toxic to them.
- Do not give paracetamol or any human pain reliever. Paracetamol is deadly to cats.
FAQ
Is my cat's watery eye contagious to my other cats?
It can be if the cause is cat flu or chlamydia. Keep bowls, bedding and cloths separate until a vet has checked.
Can people catch cat conjunctivitis?
Human infection with feline eye infections is rare, but wash your hands after cleaning your cat's eyes.
Why does my cat's eye flare up when we go away?
Stress, such as boarding or visitors, can reactivate herpesvirus in carrier cats.
Do Persians always have watery eyes?
Many do because of their face shape. Daily gentle cleaning helps, but a vet check can rule out treatable problems.
Talk with a vet
If your cat's eyes are watering and you are not sure how quickly they should be seen, a Dial A Vet veterinarian can help you decide. Talk to Dial A Vet online. A squinting, cloudy or injured eye needs an in-person vet today.
References
- Cornell Feline Health Center: Conjunctivitis and feline upper respiratory infections
- Thiry E et al. Feline herpesvirus infection: ABCD guidelines on prevention and management. Journal of Feline Medicine and Surgery, 2009
- Merck Veterinary Manual: Ophthalmic disorders in cats
- Stiles J. Ocular manifestations of feline viral diseases. The Veterinary Journal, 2014
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. If you are worried about your pet right now, contact your local vet or nearest emergency animal hospital.
