You love your cat’s big, bright eyes, but when you notice that crusty goop in the corner, it’s natural to wonder: is this normal? A little eye discharge can be harmless, but it can also signal an underlying issue. Let’s break down the most common causes of cat eye discharge, how to tell the difference, and what you can do at home.
1. Allergies: A Common Culprit for Watery Eyes
Just like people, cats can get seasonal or environmental allergies. Pollen, dust mites, mold, and even certain cleaning products can trigger watery, clear discharge. If your cat’s eyes look a little weepy but aren’t red or swollen, allergies might be the cause. You might also notice sneezing or itchy skin. For more on how allergies affect your cat’s overall health, check out our guide on why your allergic cat sneezes so much. If the discharge is clear and your cat seems otherwise fine, a gentle wipe with a damp cloth can help. But if the eyes become red or the discharge turns thick, it’s time to look deeper.
2. Eye Infections: Bacterial or Viral
Infections are a frequent cause of abnormal eye discharge. Bacterial infections often produce thick, yellow or green mucus that can crust over the eyelids. Viral infections, like feline herpesvirus, usually cause watery discharge that becomes sticky. Both can make your cat squint or paw at their eyes. If you notice colored discharge, swelling, or redness, a vet visit is important. They may prescribe antibiotic drops or antiviral medication. Never use human eye drops on your cat, as they can be harmful.
3. Blocked Tear Ducts
Sometimes the tear ducts get clogged, causing tears to overflow onto the face. This is common in flat-faced breeds like Persians and Himalayans, but any cat can develop a blockage. The discharge is usually clear and watery, but it can lead to skin irritation around the eyes. Your vet can flush the tear ducts to clear the blockage. At home, you can gently clean the area with a warm, damp cloth to prevent staining and irritation.
4. Conjunctivitis (Pink Eye)
Conjunctivitis is inflammation of the pink tissue lining the eyelids. It can be caused by infections, allergies, or irritants like smoke or dust. Symptoms include red, swollen eyes, squinting, and discharge that can be clear, white, or yellow. Your cat might also have a third eyelid showing (the nictitating membrane). This condition is uncomfortable, so prompt vet care is key. Treatment depends on the cause and may include eye drops or ointments.
Cats have a third eyelid, called the nictitating membrane, that helps protect and moisten the eye. If you see it covering part of the eye, it’s often a sign of illness or pain, not just sleepiness.
5. Foreign Objects or Injuries
A stray piece of litter, a grass seed, or a small scratch from a playmate can cause sudden eye discharge. If your cat starts squinting one eye, pawing at it, or has excessive tearing, check for visible debris. Do not try to remove anything stuck in the eye yourself, as you could cause more damage. A vet can safely flush the eye and check for corneal scratches. If your cat has allergies that make them more prone to eye irritation, you might also want to read about signs of food allergies in cats, as diet can sometimes contribute to eye issues.
6. Upper Respiratory Infections
Upper respiratory infections (URIs) are very common in cats, especially in shelters or multi-cat households. They often cause sneezing, nasal discharge, and eye discharge. The discharge can be clear at first, then turn yellow or green. URIs are usually viral but can lead to secondary bacterial infections. Keep your cat comfortable with a humidifier, clean their eyes gently, and offer smelly food to encourage eating. If symptoms last more than a few days or your cat stops eating, see a vet.
A little goop is normal, but thick, colored, or painful discharge is your cat’s way of saying something’s wrong.
When to See the Vet
While a small amount of clear discharge can be normal, you should call your vet if you see any of these signs: thick yellow or green discharge, redness or swelling, squinting or keeping the eye closed, pawing at the eye, or a change in behavior like hiding or loss of appetite. Eye problems can worsen quickly, so it’s always better to be safe. If your cat has allergies that affect their eyes, you might also consider adjusting their environment or diet. For example, some cats with food allergies do better on a hypoallergenic cat diet homemade food plan, which can reduce overall inflammation. Regular grooming, including how often to brush a cat prone to hairballs, can also help reduce allergens in their coat that might irritate their eyes.
