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Eye Infections in Cats: Types, Symptoms, Causes, and Diagnosis

Trained in dentistry, Sree is currently studying lab sciences. She enjoys researching various health topics and writing about her findings.

Be sure to examine your cat's eyes once in awhile for signs of infection.

Be sure to examine your cat's eyes once in awhile for signs of infection.

Cats are hygienic by nature. They clean and groom themselves on a regular basis, and you see them doing almost nothing but sleeping and licking their paws. Despite their meticulous grooming habits, cats are still prone to different kinds of infections. Eye infections are common in pet cats but are not usually given immediate attention, since they often look like nothing more than excessive tearing.

What Is an Eye Infection?

It is a disease in which the cat's eyes are affected by one of the following:

  • bacteria
  • fungi
  • protozoa
  • virus
  • parasite

It is a common disease complex and there are different types depending on the causes.

Types of Eye Infections

This disease affects the eyeball and the surrounding areas. In some cases, the infection begins in only one part before spreading, while in other cases, only a certain area of the eye will get infected.

Here are the following types:

  1. Conjunctivitis: Commonly known as "pink eye," conjunctivitis is an inflammation of the eye tissue called the conjunctiva. It is the pink membrane that lines the eyelids and attaches to the eyeball close to the cornea.
  2. Blepharitis: This is the infection of the eyelids. It usually leaves the cat's eyelids significantly inflamed.
  3. Keratitis: The infection and inflammation of the cornea. A simple infection of the eyelid could lead to Keratitis if it is left untreated.
  4. Uveitis: This is the infection of the uvea, the eye's vascular layer which consists of the ciliary body, iris, and choroid.
  5. Stye: A growing infection of the eyelid's sebaceous gland.
An infection can start in an isolated area and spread to other parts of the eye.

An infection can start in an isolated area and spread to other parts of the eye.

Symptoms and Signs

  • The whites of the eyeball may be red
  • There is some fluid or discharge from the eyes. It may be clear, green, or yellow.
  • The third eyelid is visible.
  • The eye is cloudy or there is a change in color.
  • Formed or forming crusty gunk around the eye(s).
  • Frequent winking and eye rubbing.
  • Cat may sneeze frequently or have some nasal discharge.

Swelling of the eye is due to fluid build-up. The enlargement of the blood vessels in the tissue causes the eye to produce discharges. If your cat is infected, it will typically look as though it is weeping. In some cases, pus is excreted to fight the infection and grows so thick that the eyelids stick together. Eye infections are irritable and often painful for the cat. A cat with conjunctivitis will often keep its eyelid partially closed and frequently rub its eye against objects, if not with its paws.

The amount of discharge and its consistency helps determine what is causing the infection. For example, thick green or yellowish eye discharge indicates a fungal or bacterial infection. On the other hand, clear watery discharge indicates an infection caused by allergies.

Eye Infection Quiz


A lot of factors can trigger an infection. It can either be irritation due to allergies or viral infections. Bacteria and viruses are the main causes, and kittens are more sensitive to them than adult cats.

The most common bacteria are Mycoplasma and Chlamydia. On the other hand, the most common viral culprits are Feline Herpesvirus Type 1 and Calicivirus. They are most commonly found in kittens with weak immune systems. For adult cats, exposure to infected felines is the most common cause. The closer a healthy cat is in contact with an infected cat, the higher its risk is for infection, especially in a crowded environment. Stressful environments like shelters also increase the risk of infection.

For grown household cats, a sudden eye infection may point to another health problem. It may be a symptom of an autoimmune disease. It could also be an early sign of more serious conditions, such as eye trauma, cancer, or a systematic viral infection, depending on the index of suspicion.

The Risks

Eye infections are common in cats, but not necessarily deadly. It can spread and affect the internal parts of the eye if left untreated. Severe cases often lead to blindness, if not impaired vision. The infection can also be easily transferred to other cats and kittens if it is viral. The most life-threatening condition that eye infections can cause is corneal ulcers.

The Diagnosis

An accurate diagnosis can be determined by a veterinarian with access to the cat's medical history, if there is any. It will help the veterinarian determine the cause of the infection and choose which diagnostic tests are most appropriate for the cat. The basic examination includes eye evaluation and a physical exam. In some cases, the veterinarian will evaluate for signs of upper respiratory infection.

  • Culture: This is a procedure in which a sample or swab of the discharge will be taken. Sometimes cell samples are scraped off from the swollen area.
  • Fluorescein Eye Strain: A process in which the veterinarian places a special orange dye into the eye in order to show ulcers or any form of foreign bodies present.

In cases where a secondary condition is suspected, the veterinarian may require some blood work or other examinations.

Bacterial eye infections often respond quickly to treatment.

Bacterial eye infections often respond quickly to treatment.

The Prognosis

It is not too difficult to treat bacterial eye infections in cats. The prognosis is often good to excellent because while viral infections are time-limited, those that are bacterial respond quickly to medical treatment. If the symptom is caused by a different disease, the prognosis may take longer depending on what the primary condition is. Whichever the case, the eye infection can usually be treated and managed, if not cured, separately.

Treatment, Care, and Management

Eye infections are rarely treated using oral medication. In most cases, an infection caused by bacteria is treated using antibiotic eye drops or a topical ointment. Viral infections are treated similarly, despite being self-limiting. However, in severe cases, anti-viral medication is given to prevent the infection from spreading and also to prevent the possibility of a bacterial infection occurring simultaneously.


An eye dropper or ointment is the preferred treatment. Eye droppers need to be applied more than thrice a day every few hours, while the ointment need only be applied twice to three times. The treatment should be consistent and the affected area must be kept clean at all times possible. There is no need to bathe the cat in order to clean its infected eye. Using a cotton ball or swab should suffice. In severe cases, other medications may be given to the cat, such as an anti-inflammatory or anti-viral treatment.


At most, it will take two weeks for the cat to fully recover. For cases where the cat has developed an ulcerated cornea, the use of agents containing Hydrocortisone should not be used. Although Hydrocortisone helps in minimizing inflammation, it will prevent the ulcerated cornea from healing and could even worsen it.

Reminder: It is not recommended to use leftover antibiotics. Even if the affected area looks a lot like conjunctivitis, it is best to seek the diagnosis of a veterinarian. Although eye infections are common in cats, other diseases (such as glaucoma) can look the same. The right diagnosis can only be done by a veterinarian who will provide the right kind of treatment.


The best way to prevent an occurrence is to keep up-to-date on the cat's vaccination and have regular checkups. Occasionally checking the cat's eyes will help prevent budding infections from getting worse.

Tips for Home Care

To keep a cat's eyes clean, you can remove crusted gunk by dipping a cotton ball or large swab in warm water. Wipe from the center, between the eyes, out towards the corner. Snipping away some of the hair around the eyes can also help reduce irritation.

For eye inspection at home, place the cat in a well-lit area. Gently roll down its lids with your thumb and check the inner lining. It should be pink and not red or white. The whites of the eyes should be clear and not clouded, hazy, or tainted with other colors. Both pupils should be equal in size, and neither eye should be partially closed.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.


ear infection on July 23, 2019:

two week old kitten holds its head two the side its ear is badly infected to the point it is gasping for breath

rlg on March 02, 2018:

good advice for someone with piles of time & money to vidit a vet. Only minimal help for those without physical or financial abilitiy. Nice to hear about more specific home remedies/treatments. Scientist already know the biology. Rest of us are looking to relieve our animals from pain, suffering and/or death.

Michelle B- Grand on April 24, 2015:

they are cute!