Among other breeds of dog, Shih Tzus and Pugs are more likely to obtain keratoconjunctivitis. Keratoconjunctivitis is a Latin word which literally means dryness of the cornea and conjunctiva. It is commonly known as dry eye.
This disease is the result of abnormal production of tears. Tears are essential because it cleanse and lubricate the cornea, carry the nutrients and also help in healing and control of the infection.
KCS is thought to be caused by some viral infections like canine distemper as well as immune mediated diseases. Other reasons of this disease are hyperthyroidism and the use of sulfa-containing drugs. Sulfa-containing drugs cause dry eyes by producing a toxic effect and the absence of this drug may improve dry eye.
Dry eye in dogs is characterized with dull and dry winking eyes. He may also experience recurrent eye infections and/or corneal ulcers. Thick, green discharge is usually seen sticking to the hair around the eye. This is usually diagnosed in one eye first and later develops in the other eye within several months. A dog with KCS tends to squint and rub his eyes and is sensitive to light. If your dog is showing any of these symptoms, it is best to see your veterinarian immediately for eye examination.
Dry eye is diagnosed based on the symptoms mentioned earlier. Also with a Schirmer tear test (STT) that measures the production of the tear production in the eye. A dog抯 normal STT values are 15 to 25 mm/minute. Dog breed that is susceptible to conjunctivitis, even without clinical signs of dry eye should undergo STT.
Treatment of KCS usually aims to restore the moisture of the eye by lubricating the eye, tear replacement, stimulating tear production, reducing bacteria overgrowth and reducing inflammation. Substitutes like polyvinyl alcohol, methylcellulose and hyaluronic acid are traditionally used to replace the lost tears. However, these solutions do not have a primary effect on the inflammation process and in the production of tears.
Recently veterinarians prescribe Cyclosporine, diluted in water and applied to the surface of the eye in order to stimulate tear production. Cyclosporine shows no undesirable effects even if used in long term basis. The use of cyclosporine may retain a dog抯 vision for years but that doesn抰 work for all patients with KCS. These treatments do not cure KCS, but are just ways to deal with this painful condition. In worst cases, dry eye can also be treated through surgery.
Dry eye seems to be a simple disease but if left untreated, might damage your dog抯 vision or may even result to complete blindness.
