Cat Eye Infections: Recognizing & Treating Your Cat’s Symptoms

When it comes to your cat’s eye health, knowing the symptoms of eye infection is instrumental in protecting her vision and quality of life. There are a variety of different causes for feline eye infection, including bacteria, a virus, or even fungi. Depending on the area of the eye that’s infected, your vet will be able to determine the cause, type of illness, and method of treatment.

cat eye infections

Common Types of Cat Eye Problems

Keratoconjunctivitis Sicca (KCS or ‘Dry Eye’): KCS, also known as ‘dry eye’, refers to any condition that impairs your cat’s ability to produce adequate amounts natural tears to keep the eye moisturized and functioning properly.

keratoconjunctivitis sicca

Conjunctivitis: If your cat has conjunctivitis (more commonly known as pink eye), the pink membrane or conjunctiva that covers the inside of her eyeball and the inside of the inner eyelids is inflamed; signs include swelling and redness, and discharge may be present. This condition is usually the result of a virus or bacterial infection.


Blepharitis: This condition refers to an inflammation or infection on your cat’s eyelids, notably the outer skin and middle portions of the eyelids, including the muscle, connective tissue and glands. Frequently, blepharitis is caused by allergies, congenital abnormalities, infections, tumors, and on occasion, inflammatory disorders.


Stye: Similar to the sties that humans suffer from, this condition is the result of an infection of the sebaceous glands in the eyelid. They typically form near the edge of the eyelid and are characterized by a red, sore lump that resembles a pimple or boil.


Keratitis: The medical terminology for inflammation of the cornea (the clear outer layer of the front of the eyeball); more specifically, non-ulcerative keratitis refers to any inflammation of the cornea that doesn’t retain fluorescent stain, a special dye that is used to identify ulcers of the cornea. Symptoms include a cloudy or watery appearance to the eye.


Third Eyelid Protrusion: If you notice that your cat’s third eyelid becomes visible or crosses her eye, it may be indicative of a wound, worms, diarrhea, or a viral infection.

third eye protrusion

Watery eyes: In the case of watery or runny eyes, the fur around your cat’s eyes may appear matted or stained with tears due to an overproduction of tears or blocked tear ducts. This may be indicative of feline allergies or an underlying medical condition.

watery eyes

Understanding the Anatomy of Your Cat’s Eyes

Understanding the anatomy of your cat’s eyes is especially valuable when caring for your pet’s infection. Not only will you have a better comprehension of her condition, but you will be able to discuss the details of illness in more thorough detail when you visit your vet’s office. Below, a breakdown of your cat’s ocular features:

  • The third eyelid: Although it is not immediately visible under normal circumstances, the third eyelid refers to a thin viscous layer that covers most of your cat’s outer eye.
  • The sclera: This is the medical terminology that refers to the whites of your cat’s eyes.
  • The cornea: Identified as the clear covering that protects your cat’s outer eye, this transparent coating is comprised of seven layers to shield one of your cat’s most delicate organs.
  • The conjunctiva: This refers to the pink connective tissue that is attached to your cat’s eyelids and sclera.

anatomy of a cats eye

Causes of Cat Eye Infections

There are many different factors to be taken into account when understanding the causes and symptoms behind your cat’s eye infections. For example, did you know that eye infections can affect one eye (known as a ‘unilateral’ infection), or both eyes (known as a ‘bilateral’ infection)?

Feline eye infections can also indicate underlying health conditions, including systemic illnesses such as calcivirus or feline herpesvirus. No matter how mild or serious the signs, it’s important to act quickly if you believe your cat has an eye infection – in addition to relieving her from any discomfort, you may also be protecting her from long-term damage, either to her vision or from other health issues she may be suffering from.

Here are several possible causes for your cat’s eye infection:

  • Feline Herpes Virus (FHV-1) and other viral infections
  • Bacterial infecti