Why Cat Eye Problems Deserve Quick Attention
Eyes are one of those things you really do not want to mess around with, whether human or feline. When my rescue cat Biscuit came home with one eye glued shut with crusty discharge, I initially thought a warm washcloth would sort things out. Two days later, the eye was worse, he was squinting even with the other eye, and the vet told me the infection had developed into a corneal ulcer that required weeks of treatment. That experience taught me that eye issues in cats can escalate fast, and early intervention makes an enormous difference in outcomes.
Cat eyes are structurally delicate and sit in a relatively exposed position on the face. They are vulnerable to infections from bacteria, viruses, and fungi, as well as injuries from scratches, foreign objects, and irritants. What starts as minor redness can progress to serious infection, ulceration, or even vision loss if left untreated. The general rule with cat eye problems is: when in doubt, see the vet sooner rather than later.
Recognizing the Signs of an Eye Infection
Knowing what healthy cat eyes look like is the starting point. Healthy eyes are clear, bright, and equally sized. The pupils should be the same size and reactive to light. The area around the eyes should be clean, without excessive tearing or discharge. The inner eyelid, or third eyelid, should not be visibly protruding across the eye.
Signs of an eye infection or other eye problem include discharge that is watery, mucous-like, yellow, or green. A small amount of clear discharge in the corners of the eyes, especially after sleep, is normal. But persistent discharge, particularly anything colored, thick, or crusty, indicates a problem. Redness of the white part of the eye or the inner eyelids, swelling around the eye, squinting or holding the eye closed, pawing at the eye, cloudiness or haziness of the normally clear cornea, and a visible third eyelid covering part of the eye are all signs that something is wrong.
One eye being affected suggests a localized issue like an injury, foreign body, or isolated infection. Both eyes being affected often points to a systemic cause like a viral upper respiratory infection, which commonly affects the eyes alongside sneezing and nasal discharge.
Common Causes of Eye Infections in Cats
Feline herpesvirus is the most common viral cause of eye infections in cats. It causes conjunctivitis, or inflammation of the tissues lining the eyelids, and can also affect the cornea. Most cats are exposed to feline herpesvirus as kittens, and like human herpes, the virus remains dormant in the body and can reactivate during times of stress, illness, or immune suppression. Recurrent eye infections in a cat are often herpesvirus flare-ups. While there is no cure for the virus itself, episodes can be managed with antiviral medication and supportive care.
Chlamydophila felis is a bacterial infection that commonly causes conjunctivitis, typically starting in one eye and spreading to the other. It is particularly common in kittens and in multi-cat environments. Treatment involves a course of antibiotics, usually doxycycline, and prognosis with proper treatment is excellent.
Mycoplasma is another bacterial cause of feline conjunctivitis. It causes similar symptoms to chlamydial infection and is also treated with antibiotics. Your veterinarian can distinguish between bacterial causes through testing or may treat empirically based on the presentation.
Corneal injuries from scratches, foreign objects, or chemical irritants can lead to secondary infections if bacteria colonize the damaged tissue. Cats who go outdoors or live in multi-cat households are at higher risk for corneal injuries from fights or rough play. A corneal injury is particularly concerning because it can progress to a corneal ulcer, which is a deeper erosion that can threaten vision if not treated promptly.
Allergies can cause watery eyes and mild conjunctivitis but are less likely to cause the thick, colored discharge associated with bacterial infections. Allergic eye symptoms are usually accompanied by other signs like sneezing, nasal discharge, or skin itching.
What to Do When You Notice Eye Symptoms
If you notice signs of an eye problem, the most important thing is to prevent your cat from further irritating the eye. If your cat is pawing at their face, an Elizabethan collar or cone can protect the eye until you can see a vet. Do not apply any human eye drops, ointments, or medications without veterinary direction. Some human eye products contain ingredients that are harmful to cats or inappropriate for their specific condition.
You can gently clean discharge from around the eye using a cotton ball or soft cloth dampened with warm water. Wipe from the inner corner outward, using a fresh cotton ball for each eye to avoid cross-contamination. This will not treat the infection but will keep your cat more comfortable and prevent discharge from crusting the eye shut.
Schedule a veterinary appointment as soon as possible. If the eye is severely swollen, the cornea appears cloudy or has a visible defect, the eye is bulging, or your cat seems to be in significant pain, treat it as an urgent matter and seek same-day veterinary care.
Veterinary Diagnosis and Treatment
Your veterinarian will examine the eye using an ophthalmoscope and may perform additional tests. A fluorescein stain test involves placing a harmless orange dye on the eye that highlights corneal ulcers or scratches under a special light. This test is quick, painless, and provides critical information about whether the corneal surface is intact.
Schirmer tear testing measures tear production to check for dry eye, which can both cause and complicate eye infections. Intraocular pressure measurement checks for glaucoma, which can present with redness and discomfort similar to an infection. Swabs for bacterial culture or PCR testing may be collected to identify the specific infectious agent.
Treatment depends on the diagnosis. Bacterial infections are treated with antibiotic eye drops or ointments, applied several times daily for one to three weeks. Viral infections may be treated with antiviral eye drops or oral antiviral medication like famciclovir. Corneal ulcers require aggressive treatment with frequent antibiotic application, pain management, and sometimes a protective contact lens or surgery for deep ulcers. Allergic conjunctivitis may respond to antihistamine eye drops or removal of the allergen.
It is critical to complete the full course of prescribed medication even if the eye looks better after a few days. Stopping antibiotic treatment early can lead to recurrence and antibiotic resistance. Follow-up appointments may be scheduled to ensure the infection has fully resolved and no complications have developed.
Kittens and Eye Infections
Kittens are especially vulnerable to eye infections, and neonatal ophthalmia, infection that develops before the eyelids fully open at around ten to fourteen days of age, is a particular concern. If you notice swelling or discharge behind closed eyelids in a very young kitten, this needs immediate veterinary attention as the trapped infection can rapidly damage the developing eye.
Kittens from shelters, outdoor colonies, and multi-cat households frequently arrive with upper respiratory infections that include significant eye involvement. Severely affected kittens may have both eyes crusted shut with discharge. Gentle cleaning with warm water several times daily is important to prevent the lids from sealing and to allow any prescribed medication to reach the eye surface.
Early and consistent treatment of eye infections in kittens is crucial because their eyes are still developing. Severe or untreated infections can cause permanent damage including corneal scarring, adhesions between the eyelid and eye surface, and in the worst cases, loss of the eye. If you are fostering kittens with eye issues, work closely with your veterinarian and do not delay treatment.
Preventing Eye Problems
While you cannot prevent all eye infections, several measures reduce the risk. Keep your cat's vaccinations current, as the FVRCP vaccine provides some protection against feline herpesvirus and calicivirus, both of which can cause eye infections. Minimize stress, which can trigger herpesvirus flare-ups. Maintain a clean living environment and wash your hands between handling different cats, especially if one has an active infection.
For cats prone to recurrent herpesvirus flare-ups, your veterinarian may recommend lysine supplementation, although scientific evidence on its effectiveness is mixed. Some vets recommend daily antiviral supplements or famciclovir during high-stress periods. Discuss preventive strategies with your vet based on your cat's specific history.
Regular gentle checks of your cat's eyes during petting sessions can help you catch problems early. Get to know what your cat's eyes normally look like so changes are immediately apparent. Early detection remains the best defense against serious eye complications.