Dry Eye in Dogs (KCS)

By Dr. Carl Palazzolo, DVM, Long Beach Animal Hospital (LBAH) 

Photos courtesy of LBAH

It is not uncommon for a dog, especially as it ages, to have a problem where not enough tears are produced to keep the eye healthy. This is called keratoconjunctivitis sicca, usually abbreviated as KCS. Kerato pertains to the cornea; conjunctivitis is inflammation of the conjunctiva, the lining of the eye and the inside of the eyelids; and sicca means “dry.”

The lack of adequate tear production causes significant pathology in the eye. It becomes dry and inflamed, and produces a tenacious mucoid discharge. The eyes are sensitive organs, and dogs that have this problem have eyes that are in constant discomfort.

A typical dog with KCS has a thick discharge from the eyes. This discharge mats the hair around the eyes and causes excoriation of the periocular area, or the skin around the eyes. The dryness also affects the cornea. It becomes susceptible to infections and does not heal well when there is an ulcer. The cornea then becomes pigmented and inflamed.


A thick mucoid discharge from the eye is a symptom of KCS.

There are many causes of KCS. Some of them include:

  •         Immune-system disease (the most common cause)
  •         Chronic conjunctivitis
  •         Viruses
  •         Heredity

KCS is diagnosed with a simple and painless test called the Schirmer Tear Test. A special test strip is put into the eye that measures tear production.


A Schirmer Tear Test is administered by a veterinarian to determine the amount of tears that the dog produces.


Schirmer Tear Test strips.

Treatment involves eye medication to cure any infection and tear replacements to moisten the eye. Cyclosporine eye medication is the mainstay of treatment, especially since the most common cause is an immune-system disease, as previously stated. These medications need to be used for the life of your dog.

Surgery is sometimes utilized in dogs that do not respond to medical therapy after several months. The surgery is called a parotid duct transposition and is performed by a veterinary ophthalmologist. It is not always successful, and patients sometimes still need medical therapy. 

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