Most cases of conjunctivitis in cats resolve on their own without medication, but there’s plenty you can do at home to keep your cat comfortable and speed recovery. The key is gentle cleaning, reducing irritants, and knowing which symptoms mean it’s time for a vet visit instead of home care.
What You’re Likely Seeing
Conjunctivitis is inflammation of the thin membrane lining your cat’s eyelids and the white of the eye. The typical signs are squinting, frequent blinking, a swollen or reddened third eyelid, and discharge. That discharge is your best clue about what’s going on: clear, watery discharge usually points to a viral infection or irritant, while thick, dark-colored or yellowish-green discharge suggests bacteria may be involved.
The most common culprit is feline herpesvirus (FHV-1), which causes upper respiratory symptoms alongside the eye irritation. Cats who’ve had it before can have flare-ups during stress. Bacterial infections, allergies, and household irritants like cigarette smoke or strong cleaning products can also trigger it.
How to Clean Your Cat’s Eyes Safely
Gentle cleaning is the single most useful thing you can do at home. Use a soft, damp cloth or cotton ball soaked in warm water. Wipe from the inner corner of the eye outward, using a fresh cloth or cotton ball for each eye so you don’t spread infection between them. Do this two to three times a day, or whenever you notice discharge building up. Crusty buildup can seal the eyelids shut if left alone, which traps bacteria and makes things worse.
A tiny amount of diluted baby shampoo on the cloth can help dissolve stubborn crust around the eye area, but keep it away from the eye itself. Never use human eye drops, medicated ointments, or any over-the-counter product meant for people unless a vet has specifically told you to. Some common ingredients in human medications, including certain decongestants and antihistamines, can cause elevated heart rate, seizures, and other serious reactions in cats.
Reduce Irritants and Stress
Since viral conjunctivitis flares up during periods of stress, creating a calm environment genuinely helps your cat heal. Keep your cat in a quiet room away from other pets if possible, especially during the first few days. Minimize loud noises, household disruptions, and anything that tends to make your cat anxious.
Remove airborne irritants from your home. Cigarette smoke, scented candles, aerosol sprays, and strong cleaning chemicals can all aggravate inflamed eyes. If you’re using dusty cat litter, consider temporarily switching to a low-dust variety. Good airflow matters too. A room that’s not too dry and not too stuffy gives irritated mucous membranes the best chance to recover.
Make sure your cat is eating and drinking well. Cats with upper respiratory infections sometimes lose their appetite because they can’t smell their food. Warming wet food slightly can make it more aromatic and appealing.
L-Lysine Supplements
If your cat’s conjunctivitis is linked to feline herpesvirus, an L-lysine supplement may help reduce symptom severity. In a controlled study, cats given 500 mg of lysine twice daily developed less severe conjunctivitis from FHV-1 compared to cats that received a placebo. The supplement didn’t eliminate the virus, but it made the illness milder.
L-lysine is available as a paste, treat, or powder you can mix into food. It’s generally well tolerated. That said, results in broader clinical research have been mixed, and some veterinarians are more enthusiastic about it than others. It’s a reasonable low-risk option to try, particularly for cats with recurring herpesvirus flare-ups, but it’s not a substitute for veterinary treatment when symptoms are severe.
Preventing Spread in Multi-Cat Homes
Both viral and bacterial conjunctivitis spread easily between cats through direct contact, shared food bowls, and contaminated bedding. If one cat is affected, isolate them from your other cats until the discharge clears. Wash bedding, food dishes, and water bowls with hot water daily. Clean litter boxes more frequently than usual and wash your hands thoroughly after handling the sick cat before touching your others.
Feline herpesvirus is especially persistent. Once a cat is infected, it carries the virus for life and can shed it intermittently, particularly during stress. Keeping all your cats up to date on vaccinations won’t prevent herpesvirus entirely, but it does reduce the severity of symptoms if they’re exposed.
Signs That Need Veterinary Attention
While mild conjunctivitis often clears up at home within a week or so, certain symptoms signal something more serious. Cloudiness of the cornea (the clear surface of the eye) is a red flag. It can indicate a corneal ulcer, which causes discharge, light sensitivity, squinting, and sometimes visible changes to the eye’s surface. Cats with ulcers may paw at their face or act like they’re having trouble seeing. Corneal ulcers can worsen rapidly and lead to permanent damage without treatment.
You should also seek veterinary care if your cat develops thick green or yellow discharge that isn’t improving after a few days of home cleaning, if the eye looks painful rather than just irritated, or if your cat stops eating, becomes lethargic, or develops a fever alongside the eye symptoms. Veterinary guidelines recommend a period of observation for mild cases, but when mucopurulent discharge is accompanied by fever, lethargy, or loss of appetite, antibiotics are typically warranted.
One eye affected is more likely to be an injury or localized problem. Both eyes affected alongside sneezing and nasal discharge points to an upper respiratory infection, which is usually viral and self-limiting but can develop a secondary bacterial component that needs treatment.
What a Vet Visit Looks Like
If you do end up at the vet, the visit is straightforward. They’ll examine the eyes, often using a special dye that glows under blue light to check for corneal ulcers. If bacteria are suspected, your cat will likely go home with antibiotic eye drops or ointment. For herpesvirus-related cases, antiviral eye medication may be prescribed instead.
One practical note worth knowing: cats are prone to throat irritation from pills and capsules that get stuck on the way down. If your vet prescribes oral medication, give it with a small amount of food or follow it with a syringe of water to make sure it reaches the stomach.