Cat Eye Discharge: 9 Common Causes

One of the most common feline conditions veterinarians see is patients with “goopy eyes,” otherwise known as eye discharge in cats. Cat eye discharge has several possible causes, all of which can cause similar signs, requiring a visit to the veterinarian for a diagnosis.

What is Cat Eye Discharge?

Your cat’s eye is a delicate structure. To protect itself from drying out, the eye is regularly lubricated with tears, which are drained away. Cat eye discharge happens when this process goes wrong. It can be due to too many tears being produced, the drainage route being blocked, or a cat eye infection. 

Although common, eye discharge in cats indicates something isn’t happening correctly. All cats with eye discharge should have a check-up with a veterinarian. How quickly that check-up needs to happen depends on how long your cat has had watery eyes – if your cat’s eye discharge is new, they should go to the veterinarian as soon as possible. Kittens and new cats to the home with eye discharge should also head to a vet as soon as possible. If an adult cat has had the eye discharge for months or years, they should still go to the vet, but as long as there are no other symptoms, it can usually wait a week or two until a convenient time.

What Does Eye Discharge in Cats Look Like?

Cat eye discharge can vary in color and thickness. Watery eye discharge is usually caused by overproduction or overflow of tears. You might not see the tears themselves, but the fur on one or both sides of the nose will be wet and crusty when dry. If your cat has white fur, these “tear stains” may appear pink or red-brown due to pigments in their tears. 

Eye discharge from an infection is usually yellow or green and is usually thicker or sticky. Brown eye discharge can also be from a cat eye infection. It dries very crusty. You’ll see this collecting in the inner corner of your cat’s eye, spilling over and collecting alongside the nose.

A cat with bloody eye discharge or red eye discharge should visit the veterinarian urgently, as it’s likely they have an eye injury and are in some pain.

Because the fur and skin are constantly wet, if a cat has eye discharge, they often have sore or infected skin under their eyes. This can irritate, so you may see your cat rubbing their face with their paws or using furniture to itch the area. 

You may also see cat pink eye, also known as conjunctivitis. This is when your cat’s conjunctiva (the pink inside of the eyelids) becomes swollen and visible. Conjunctivitis isn’t a diagnosis, it’s a symptom – your vet will still have to find out the cause. 

Causes of Cat Eye Discharge

Feline Upper Respiratory Infections (‘Cat Flu’)

The most common cause of cat eye discharge is feline upper respiratory infection, commonly called cat flu. While several infectious diseases can cause cat flu, the most common is feline herpes virus. This virus causes other flu symptoms, too – cats frequently sneeze, have discharge from the nose, and are generally under the weather. Eighty percent of cats never get rid of the virus entirely – it comes back when they’re stressed or their immune system is weakened. In some cats, all the symptoms will return, but many will only get signs of conjunctivitis (sore, swollen eyes and eye discharge from one or both eyes). 

Cat sneezing and eye discharge are usually cat flu, but that doesn’t mean it should be taken lightly – feline herpes virus can cause blindness when severe.

Trauma and Injuries to the Cornea or Eye

Another common cause of eye discharge in cats is an injured cornea. The cornea is the outer surface of the eye. Scratches to the cornea are very painful and cause the eye to water significantly, causing a watery eye discharge, although this can go yellow or green once infection sets in. Cats will often also hold their damaged eye closed in a squint. The damage is sometimes visible to the naked eye but often needs a special dye to diagnose correctly.

If your cat is squinting in one eye and has discharge, your cat will need urgent medical attention.

Foreign Body

Foreign bodies (such as another cat’s claw from a fight) are painful, no matter where they lodge. Cats with a foreign object in their eye are likely to be squinting, blinking a lot, and holding their eye closed, with plenty of watery discharge. If not treated, the discharge will become thicker and yellow as infection occurs. 

A foreign body in the eye often causes injury to the cornea, so your cat may have both conditions. Both need urgent treatment.

Blocked Tear Ducts

Another reason for cat eye discharge is a blocked tear duct. The tear duct is a small tube that drains the normal tears from the eye into the nose. If this tube is blocked due to an infection or inflammation, tears won’t drain properly and instead spill over, causing eye discharge. This type of discharge is usually thin and watery, as it’s just normal eye lubricant. 

Although blocked tear ducts in cats aren’t an emergency, the type of discharge is very similar to other more serious conditions, so you should always get a diagnosis from a veterinarian.

Allergies and Irritants

Just as our eyes water when we get hay fever, so will a cat’s. If your cat’s eyes only water at certain times of year, allergies may be involved. You may also see sneezing or asthma in these cases. Airborne irritants can also cause watery cat eyes – bleach, ammonia, and other strong scents can cause a cat’s eyes to water. 

Allergies and irritants aren’t usually emergencies, but it’s still best to see a veterinarian to rule out something else. Remember that some irritants may also be toxic – for instance, some essential oils often used in scented products are toxic to cats [1]. This could cause eye-watering but also cause other symptoms like drooling and vomiting – you should seek treatment urgently.

Uveitis

Uveitis happens when a particular eye part (the iris and ciliary body) becomes inflamed. It causes eye discharge in cats because it’s so painful – you’ll also see blinking and squinting in one or both eyes, and the discharge is usually clear. Uveitis is usually caused by an infection (viruses, bacteria, and fungi have all been implicated to varying degrees in different countries). Eye damage, eye tumors, diabetes, and high blood pressure are also sometimes at fault. Uveitis needs urgent medical attention because it’s extremely painful and can result in blindness if left untreated.

Eyelid Problems (Entropion)

Entropion is a condition where the eyelid rolls in, causing the eyelashes to rub the eyeball. It’s very irritating, and affected cats will have continually watery eyes. They’re also prone to eye infections, thickening the discharge and turning it yellow or green. Cats are usually born with this condition, although anything that changes the shape of the eyelid (such as a tumor or swelling) can cause entropion. A vet should assess possible entropion, which can cause corneal injury, recurrent infections, and blindness.

Face Shape (Conformation)

Eye discharge is common in some cat breeds, especially brachycephalic (short-nosed) breeds like the Persian. In one study, 83 percent of Persians and Exotic Shorthairs had eye discharge [2]. This is likely due to the shape of their face making eye injury more common, increased likelihood of entropion (which affected 32 percent of the cats in the study), or their squashed noses compressing their tear ducts. 

Even if you think your cat’s eye discharge is due to their breed, you should get them assessed by a vet to rule out entropion or other conditions making it worse.

Dental Disease

Because the tear duct runs from the corner of the eye down to the nose, it passes very close to several tooth roots, especially the upper canines. Severe dental disease, especially a tooth root abscess, can cause swelling in the upper jaw [3]. This compresses the tear duct and causes eye discharge in cats. 

A vet should assess eye discharge related to dental disease and treat it as it’s very painful.

Eye Discharge in Cats Treatment

Cat eye discharge treatment depends on the exact cause and varies from no treatment to surgery.

For eye discharge caused by face shape, no treatment is usually needed. Cat flu cases may also receive no treatment if the infection appears entirely viral, without evidence of a secondary bacterial infection.

In many cases, cat eye drops will be necessary. Depending on the exact medication used, these can provide pain relief, reduce inflammation, or help combat eye infections. Corneal injuries, secondary eye infections, and severe cat flu will usually be treated with antibiotic eye drops.

For some cases of eye discharge, surgery will be recommended. This is the case for eye discharge caused by dental disease, entropion, or foreign bodies in the eye. Blocked tear ducts can also be flushed under sedation, removing the blockage. 

Once your veterinarian has determined the cause of your cat’s eye discharge, they will discuss the treatment options. If you have cost concerns, please discuss these with your vet at the earliest opportunity – they will help you to find an affordable option.

Cat Eye Discharge Home Remedies

You should never use home remedies for cat eye discharge before speaking to a veterinarian. This is because some causes of cat eye discharge can result in blindness without proper treatment. 

Some cat eye conditions can be helped at home once your veterinarian has diagnosed the problem.

If your veterinarian diagnoses your cat with eye discharge caused by cat flu, improving their diet to help their immune system cope may help to prevent flare-ups. 

If your cat has eye discharge caused by their face shape, you may not be able to improve the discharge, but you can help by keeping the skin clean to prevent infections. Cooled boiled water on a cotton pad can be used to clean the eye discharge. Your vet might also recommend a wipe or solution to help keep infections at bay. 

How to Prevent Eye Discharge in Cats

There are several things you can do to prevent cat eye discharge and protect your cat from developing this condition. 

The first is to know the risks. As mentioned, flat-faced cat breeds are prone to developing cat eye discharge. So if you just can’t resist those adorably squished faces, then be extra vigilant about care and prevention measures for these breeds. 

No matter what shape your cat’s face is, one key way to combat eye discharge in cats is to have your cat properly vaccinated. The FVRCP vaccine, a core vaccine for cats, can help protect against cat flu, one of the leading causes of eye discharge in cats. 

But bear in mind that there are many causes of cat flu, and they may already have caught it, so the vaccination won’t prevent every cat flu case.

You can also prevent dental disease by regularly brushing your cat’s teeth and inspecting their mouth for bad smells or tooth damage. This means the disease can be treated before it develops into an abscess that damages the tear ducts.

There isn’t much that can be done to prevent accidental damage, trauma, and foreign bodies. Not letting your cat out may help, but damage can still occur in the house. Airborne irritants are also more likely if your cat spends a lot of time indoors – if this is the case, check your cleaning materials carefully and avoid using anything too strong. 

Conclusion

Eye discharge in cats is very common, as it can occur for several reasons. You should never attempt home treatment before attending a veterinary clinic for a proper diagnosis, as delaying adequate treatment can result in blindness. It’s impossible to prevent all the causes of eye discharge, but ensuring your cat receives proper care throughout their life and keeping up with their vaccinations can help you reduce the risk of eye discharge in your cat.

References

1. Benson, Kia. “Essential Oils and Cats.” Pet Poison Helpline, 6 Mar. 2020, www.petpoisonhelpline.com/blog/essential-oils-cats/.
2. Anagrius, Kerstin L., et al. “Facial Conformation Characteristics in Persian and Exotic Shorthair Cats.” Journal of Feline Medicine and Surgery, vol. 23, no. 12, 2021, p. 1089–1097, https://doi.org/10.1177/1098612X21997631.
3. Anthony, James M. G., et al. “Nasolacrimal Obstruction Caused by Root Abscess … – Wiley Online Library.” Wiley Online Library, 7 Mar. 2010, onlinelibrary.wiley.com/doi/abs/10.1111/j.1463-5224.2009.00754.x.