Discharge, unusual blinking, or rubbing of the eyes may be the sign of a cat eye infection. Understanding the symptoms is key to treating this common condition.

By Brendan Howard
August 24, 2020
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Your cat's gorgeous eyes are suddenly showing some signs of irritation. They’re looking a little goopy—clear, yellow, or green discharge might be pooling in the corners of the eyes and on the eyelids. Perhaps she’s squinting or blinking, or those cute little paws are rubbing one or both eyes more than usual. 

You might be wondering if it’s an eye infection. Even worse—is it contagious? Before turning to an untested home remedy or raiding your medicine cabinet for a treatment that’s meant for humans, consider the different conditions that can cause eye trouble in cats. You need a solid diagnosis from a professional before tackling your cat's eye trouble, and here's why.

Understand the Signs of Cat Eye Infection

Veterinarians say the first signs of an eye infection owners notice are pretty straightforward, and aside from the cat's third eyelid (which is known as the nictitating membrane), these signs might sound a lot like humans’ when we get an eye infection: 

  • The white of your cat's eye may show some redness. 
  • You may see eye discharge that's clear, yellow, or green. 
  • You may see excessive blinking, or it may look like your cat is winking at you. 
  • Your cat’s third eyelid—which actually closes sideways, instead of up and down like our eyelids—may be covering up more of the eye than usual. 
  • And if their eye problem is tied to an upper respiratory infection, your cat may also be sneezing or experiencing some nasal discharge as well.

Some eye problems can go away on their own, but because many eye conditions are indicative of something more serious—like diseases that can lead to blindness or worse—diagnosis is crucial. 

"Most cases are going to require intervention by a veterinarian," says Ernie Ward, DVM, a writer, podcaster, pet nutrition advocate, and veterinarian who works with cats at animal rescue groups in North Carolina. "Eyes are emergencies. Eye [problems] can be intensely painful. I can't overstress that."

Here’s how to know what could be causing your cat’s eye trouble so you can get it treated quickly and effectively.

What Causes Eye Infections in Cats? 

Potential causes for your cat's eye infection or condition can include:

Upper respiratory infections

Upper respiratory infections are caused by viruses (like the contagious feline calicivirus) as well as pneumonitis, rhinotracheitis (which is caused by feline herpesvirus—not the type that humans have), or various bacteria and protozoa. Similar to respiratory infections that affect humans, signs can include sneezing and runny nose, in addition to inflammation and discharge of the eyes. Most upper respiratory infections are seen more frequently in young cats (who may have weaker immune systems or who have not yet been vaccinated) or those exposed to high-stress environments, like shelters. 

Conjunctivitis ("pink eye")

Known as inflammation of the inside of the eyelid and the exterior of the eye, conjunctivitis can cause redness, swelling, and discharge. Your cat's eyes may also be more sensitive to light, which leads to blinking, squinting, or trying to keep the eye closed. But if you’re worried about catching "pink eye" from your feline friend, small-animal veterinarian Amber Aher, BVetMed, who works at VCA Salem Animal Hospital in Salem, Ore., says it’s possible—but not likely. "While it's very uncommon, certain cat bacterial species (Chlamydia felis) may cause mild conjunctivitis in people,” she says. “But eye diseases in cats often have a viral cause and aren't contagious." 

Corneal disorders

The dome-shaped surface of the front of the eye can get irritated, traumatized, or ulcerated (an open sore), causing cloudiness of a cat's otherwise clear eyes. "If the inside of the eyeball is cloudy, not in a discrete part [like a developing cataract] but diffused throughout, that's an immediate medical emergency," says Ward. 

Epiphora

Pronounced "eh-PIFF-urr-uh," epiphora is a pretty word for too much watering or tears in the eye—could be a result of blocked tear ducts, allergies, conjunctivitis, or other conditions. Ward likens the condition to that of a clogged bathtub. “It's like water that won't go into a drain and runs out the side of your shower," he says. The opposite problem, dry eye, can lead to redness, inflammation, and blindness if left untreated. 

Uveitis

This painful inflammation affects a number of parts of the eye that don't include the eyelid or cornea, uveitis can be caused by trauma, cancer, immune system disorders, or infections.

Other culprits can include feline infectious peritonitis, allergies, foreign bodies (something stuck in the eye), or damage or inflammation to a cat's third eyelid.

Correct Diagnosis is Key 

The long list of potential conditions that aggravate, inflame, and damage a cat's eyes means that getting the correct diagnosis from a vet is crucial. And because the viruses and bacteria that cause cat eye infections can be highly contagious to other cats as well, figuring out what's wrong is the first step to making it right—the earlier, the better. Home remedies without a medical diagnosis might sound tempting, especially when considering cost, convenience, or the stress a trip to the vet can cause. But proper treatment is crucial for making sure your cat has the best chance at a full recovery. 

"Certain diseases of the eye can cause loss of vision or irreparable damage to the eye, requiring surgical removal to alleviate pain—both of which are significant welfare concerns for the cat," Aher says. "Eye diseases may also reflect a systemic illness and can be an indication that more diagnostics are needed."

Ward agrees: "If a cat is squinting, has red eyes or is pawing at the eyes, don't put anything in the eye before the veterinarian determines the cause. Putting the wrong medication in an eye wound can slow down healing."

An evaluation of your cat's eyes to check for signs of illness, infection, or injury is the first step. Blood tests and tests of the cat's eye discharge or infected skin cells may also be required to determine what’s wrong. 

Treatment and Prevention of Eye Issues

Once your vet knows what's causing your cat's eye discharge, red eyes, irritation, or pain, they’ll be able to consider the right treatment—and whether any home remedy is appropriate. Never give your cat eye drops, ointments, antibiotics, or other medicine unless directed to do so by a veterinarian. 

Here are some treatments that might be called for depending on the diagnosis: 

Upper respiratory infections

What's causing the infection will determine the treatment, but help could come in the form of eye drops or ointments, antibiotics, decongestants, or fluids. Remember, some of these infections can be contagious, so follow your veterinarian's recommendations about how to keep a sick cat away from other cats and pets in the household. "In multi-cat households, with viruses, it often means every cat already has it," says Ward. "And I know it can be nearly impossible to keep them separated. The viruses can also be cyclical, so many of these infectious eye problems may recur." 

Conjunctivitis ("pink eye")

If allergies or an exposure to a chemical is the problem, a steroid ointment may help bring down inflammation in the eye, while antibiotics may be another solution for bacterial infections. Because those steroids can do harm to the vulnerable inside of the eyeball if there's a wound in the cornea, Ward says veterinarians will perform a special dye test to check for damage that can happen through regular activities, like when a pet runs through tall grass or weeds, or gets sand or dirt stuck in their eye.  

Corneal disorders

Because the problem could be an infection, injury, or an ulcer, an issue like a corneal disorder needs careful diagnosis. Treatment might include a combination of keeping the cat's eyes clean (moistening a soft cloth, cotton ball or bathroom tissue to gently wipe away secretions around the eye) along with antibiotics, medicine to help the eye heal, or even surgery, if there is scarring or continuing damage to the eye. The good news, says Ward, is that the cornea is fast-healing. "The body can't afford to lose its primary sensory input," he says. 

Epiphora

If the excess watering is due to a blockage, a veterinarian can flush the tear ducts while your cat is under general anesthesia (unconscious), while infections may call for antibiotics. "The most common cause of watery eyes I've seen is seasonal allergies, and anti-inflammatories can reduce swelling of those ducts," Ward says. Dry eye, on the other hand, a potential sign of injury or disease, can range from artificial tears to eye drops, ointments, antibiotics, and drugs that suppress a cat's immune system (if that's the cause). "[Dry eye] is often the result of an immune-system problem," he says, and medications can help. 

Uveitis

The cause of this inflammation of the eye's uvea—which includes the iris, the choroid that nourishes that retina and the ciliary body, which produces fluid in the eye—can be difficult to diagnose. If your cat is experiencing pain, treatment may include pain-relieving eye medicine, anti-inflammatories as well as medication and antibiotics to manage underlying infections. 

If you find it difficult to administer medicine that a veterinarian prescribes for any of the above conditions, you're not alone. Veterinarians understand how challenging it can be to give your cat medication, whether it’s getting them to swallow a pill or putting ointment or drops into your cat's eye. Aher explains that this can be especially hard if you feel like your relationship with your cat is negatively affected by administering medication. In other words—the cat hates it, and now you’re worried your cat is starting to hate you. If that’s the case, work with your veterinarian to find solutions that can help you get the medicine where it needs to go.

"There can be differences between solutions or ointments, with most clients finding it easier to administer drops," Aher suggests. 

Home Remedies for Cat Eye Infections

Last but not least, it's important to totally rule out two home remedies circulating on the internet for cat's eye infections.

First, don't get your "neos" mixed up. Neosporin, a topical skin ointment for humans, does not belong in the eyes of people, cats, or anybody else (its product label forbids use in eyes). You may see Neomycin listed as an ingredient in some antibiotics for cat eye infections. But they're different products for different things—just don't mix them up!

Second, apple cider vinegar should not be used to treat your cat’s eye infections. Not only is it ineffective, it’s also dangerous—and can cause chemical burns to a cat's cornea as well as cataracts and glaucoma if the vinegar penetrates even deeper into the eye. Vinegar doesn't belong anywhere near a cat's eye, or yours for that matter. 

When it’s Time to Call the Vet

Cat eye infections can cause discharge, irritation, and pain and are caused by a number of factors. If an eye condition persists for longer than a day and isn't getting better, it's time to make an appointment with a veterinarian to find out what's wrong, so you can get it treated right away.

Ward advises pet owners to be wary of using old eye medications that were previously prescribed to treat a new problem that crops up. "I've seen so many cases where the pet owner has leftover eye medication, and when the [pet] is squinting and pawing at red eyes, they try it," Ward says.

But because eye problems in cats can be caused by so many different issues—from allergies to corneal scratches—using that old medicine without an examination by your vet can cause serious problems and even further damage to your cat’s eye.