What is keratoconjunctivitis sicca?
Keratoconjunctivitis sicca (KCS) or "dry eye" is the failure of the tear glands to produce enough liquid tears to keep the eye moist and healthy.

What causes keratoconjunctivitis sicca?
The most common cause for KCS is thought to be an autoimmune reaction. The immune system launches a misdirected attack on the tear glands; the triggering event is unknown. Occasionally, certain drugs may induce a dry eye. In most instances, KCS requires life-long treatment to prevent ocular discomfort and secondary ophthalmic problems.

Are certain breeds of dogs prone to keratoconjunctivitis sicca?
Yes. The American Cocker Spaniel, Bulldog, Lhasa Apso, Miniature Poodle, Shih Tzu and West Highland White Terrier are prone to KCS, although any breed of dog may be afflicted with KCS.

How do I know if my pet has keratoconjunctivitis sicca?
Most dogs with KCS will have a constant heavy, white or yellow discharge from the affected eye. A dry eye is more prone to bacterial infections, conjunctivitis, and corneal ulcers. Eyes that are dry for several months develop corneal scarring and pigmentation, in severe cases this results in obstruction of vision.

A poodle with mucopurulent discharge and chronic pigmentary keratitis secondary to Keratoconjunctivitis Sicca

Chronic pigmentary keratitis and corneal edema secondary to Keratoconjunctivitis Sicca

How is keratoconjunctivitis sicca diagnosed?
A Schirmer tear test is used to diagnose KCS and to measure response to treatment. A small strip of paper is placed in the conjunctival sac for 60 seconds. The amount of tears wicked up by the paper in one minute is measured. A normal result for a Schirmer Tear Test is 15-25mm/min in dogs and 7-12mm/min in cats.

What is the treatment for keratoconjunctivitis sicca?
KCS is treated with medication and in refractory patients surgery can be performed. Medical treatment can sometimes reverse the autoimmune reaction and help stimulate tear production. In pets that do not respond to therapy, a parotid duct transposition surgery may be considered. This surgery involves re-routing the parotid salivary gland duct from the mouth to the eye, so that the eye is lubricated by saliva. This surgery frequently results in excessive tearing and, consequently, a wet face. Regardless of the treatment chosen, KCS is a chronic problem that often requires long-term maintenance therapy.