Canine Dry Eye Explained: All About Keratoconjunctivitis Sicca (KCS)

Canine dry eye, or keratoconjunctivitis sicca (KCS), is a common eye ailment in dogs. Dry eye is a reduction in natural tear production causing drying and inflammation of the cornea. If left untreated, chronic dry eye can lead to ulceration of the cornea, infection and potentially the loss of vision.

Causes of Dry Eye

There is any number of causes of dry eye. The majority of cases are caused by deterioration of the tear ducts. Other causes include:

  • Hypothyroidism
  • Drug toxicity
  • Reaction to medication
  • Systemic disease
  • Chronic conjunctivitis
  • Congenital disease
  • Breed predisposition

In some cases the cause is never identified, but the condition is still treatable.

While any breed of dog can be subject to dry eye, there are several breeds that have inherited a greater probability of contracting the condition. These breeds include American Cocker Spaniel, Bulldog, Lhasa Apso, Pekingese, Pug, Shih tzu and West Highland White Terrier.

Symptoms of Keratoconjunctivitis Sicca

Symptoms that present themselves will vary depending upon how long the eyes have been impacted by dry eye. Common symptoms include:

  • Redness and swelling of the area around the eye (the conjunctiva)
  • Squinting and excessive blinking
  • Thick, yellowish discharge from the eye
  • Ulceration or cloudiness of the cornea
  • Secondary bacterial infections
  • Prominent third eyelid
  • Impaired vision

Diagnosis of Dry Eye

Although there are many causes of dry eye, the diagnosis can be confirmed with a Schirmer tear test. Small strips of an absorbent paper are inserted between the eyelid and the eye, absorbing tears and indicating the level of tear production. Based upon the results of the test, the veterinarian can confirm KCS and prescribe appropriate treatment.

Treatment of Canine Dry Eye

Once diagnosed, treatment is a matter of cleaning the eyes and administering medication. The dog owner should make sure that any discharge is cleaned away with a warm, moist cloth. This is especially important prior to administering the medication. The most common treatment for dry eye is administering Cyclosporine ointment, promoting an increase in tear production. The ointment may be supplemented by tear replacement products such as lubricating ointment or artificial tear eye drops.

Depending upon the extent of the condition, additional treatment may be necessary. If a secondary bacterial infection has set in or a corneal ulcer has developed, antibiotic drops will be required to treat or prevent infection. If the thick discharge is persistent, additional medication may be necessary to decrease the mucous production. In some cases where medicinal treatment isn't successful, surgery may be an option in order to reroute a duct from the salivary glands.

Any dog with dry eye should be examined and a Schirmer tear test conducted on a regular basis to ensure that the treatment continues to be effective.

Canine dry eye is a condition that impacts many dogs. Depending upon the cause, KCS can be temporary or a lifelong condition. Left untreated, dry eye can become progressively uncomfortable, causing infections and potentially irreparable damage. Corneal ulcerations and corneal scarring can ultimately lead to loss of visual acuity and blindness. The best course of action is to seek veterinary advice and to begin treatment immediately. Once treatment has begun, your dog should see improvement and move on to a life with healthy, comfortable eyes.