Keratoconjunctivitis: Does My Cat Have an Eye Infection?

Keratoconjunctivitis is an awfully long word that basically means any inflammation (“itis”) of both the cornea (“kerato,” the transparent part of your eye that you see through) and the conjunctiva (the pink mucous membrane that covers the insides of your eyelids and attaches to the opaque, white part or “sclera” of the eye). You probably know from your own experience that your eyes are really, pretty vulnerable to trauma and irritation from wind, dryness, infections, foreign bodies and anything in between. It’s not surprising, then, that your cat’s eyes are also sensitive to developing keratoconjunctivitis.

What do you see if you cat has eye inflammation?
Again you can probably guess, based on your own experience. Inflammation causes:

  • Redness
  • Swelling of the eyelids and conjunctiva
  • Itchiness (your cat may rub her face and eyes)
  • Pain
  • Squinting (either from pain or from sensitivity to light)
  • Discharge from her eyes (clear, excessive tearing or thicker mucous) that might even ‘glue’ her eyelids closed especially when she has been sleeping
  • Cloudy appearance of the corneal surface
  • Decreased visual acuity

Not all symptoms will occur in all cases and the condition may only exist in one eye or in both eyes, depending on the cause.

What causes eye inflammation in cats?
Remember, since this is an “itis,” it can be caused by anything that causes irritation or inflammation to the eye.  Some causes include:

What is keratoconjunctivitis sicca (KCS)?
Unlike transient dry eyes from environmental conditions or irritants, Keratoconjunctivitis sicca (KCS) is a specific, medical condition that requires long term treatment. It is a common cause for keratoconjunctivitis in dogs, but it is a rare eye disease in cats1.

KCS can, however, occur as a consequence of feline herpes virus infection (FHV) which is a very common upper respiratory infection in cats. In fact, FHV may be the most common cause of chronic keratoconjunctivitis in cats, reports Dr. Rhea Morgan of Verzijlenberg Veterinary Hospital. When the virus infects the cornea and the conjunctiva, clinical signs range from mild conjunctivitis to severe illness:

  • Fever
  • Anorexia
  • Marked inflammation
  • Discharge in the eyes (even ulcers and adhesions)

How is keratoconjunctivitis diagnosed and treated?
Your veterinarian will, of course, need to do a thorough examination of your cat’s eyes (checking for any abnormalities, ulcers, and adequate tear production and vision deficits). In addition, a complete physical examination and other tests may be needed to rule out any suspected underlying problems that might be contributing to the inflammation in your cat’s eye(s) so those problems can be addressed while specific treatment for the ocular symptoms are instituted.

In cases of FHV infections, small scrapings of tissues from your cat’s eyes may be examined for evidence of the virus, and special blood tests for the virus can be performed.

In general, you can expect that the application of some form of eye drops or ointments will be required to bring your cat relief. The type of medication may vary depending on the presence or absence of infection, ulcers, cloudiness, etc. FHV cases are treated with anti-viral medications. And if KCS occurs, replacement artificial tears need to be instilled in the eye multiple times a day--at least temporarily and in many cases forever going forward.

Your ultimate goal is not only to keep your cat comfortable in the short term but also to preserve vision for the long haul. Keratoconjunctivitis should be a treatable, controllable problem, even if it isn’t entirely curable, but managing it can require a significant commitment; it is VERY important that you follow your veterinarian’s recommendations and instructions in order to obtain the very best outcome possible.

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.


  1. "Keratoconjunctivitis Sicca." Vetbook. N.p., n.d. Web. 02 Apr. 2015.


Reviewed on: 
Thursday, April 2, 2015