Definition of Dry Eye
Dry eye, medically called keratoconjunctivitis sicca or KCS, is a painful condition involving abnormal function of the lacrimal glands, which normally produce tears. KCS is probably immune-mediated, which means that the dog’s immune system targets and attacks its own tear glands. How and why this happens is not well-understood. Dogs with KCS don’t produce enough tears to keep their eyes lubricated. The outer covering of their eyeballs (the cornea), and the lining of their eyelids (the conjunctiva), become dry, rough, red, inflamed, sensitive and fragile. Unfortunately, dry eye is common. Affected dogs are always uncomfortable. Their eyes are irritated, itchy, scratchy, painful and red. As the condition worsens, the cornea can ulcerate and slough because of the lack of adequate lubrication. Owners who suspect that their dog has dry eye should consult with a veterinarian, because this condition usually is manageable.