Keratoconjunctivitis Sicca (KCS)

from the AMCA Newsletter, Volume 44, No 7. July 1996 — Health Column written by Jocelynn Jacobs-Knoll, DVM

Storm was a 4 year old male, castrated Alaskan Malamute mix who was brought into his veterinarian for an eye consultation. Storm has always had some discharge coming from his eyes, however, his owner noticed in the last few months that the amount of discharge was increasing and his eyes were beginning to look cloudy. They decided to have their veterinarian evaluate Storm to determine what was causing the clinical signs.

Storm's veterinarian did a complete exam of both of his eyes, and they appeared to have a significant amount of yellowish tan discharge built up in the corners. Both corneas also appeared quite hazy. The conjunctiva (inside section of the eyelids) were also inflamed and irritated. Using an ophthalmoscope, he determined that the interior of the eyes appeared to be normal. His next step was to do additional tests on Storm's eyes. The first test was a Schirmer Tear Test to see if Storm was producing enough tears to lubricate his eyes. With this simple and painless test, a small strip of Schirmer Tear Test paper is placed in the inner lower lid of each eye. Then after 1 minute, both strips are removed and compared to a scale for normal tear production amounts. Normal dogs produce enough tears to wet at least 15 mm of the length of the paper (in fact most dogs wet between 15 mm and 25 mm in a minute), but dogs that don't produce enough tears, have values of less than 15 mm (with the average being around or below 10 mm). In Storm's case, both eyes produced only about 8 mm of wetting on the strip. These results revealed he was not producing enough tears to lubricate his eyes, and that was the cause of the clinical signs he was showing. The second test his veterinarian ran was a Fluorescein Stain test to check for ulcers on the corneas because of the lack of tears. This test also came out positive as Storm had a small lesion beginning to appear in the center of one of his eyes.

With the test results obtained from the Schirmer Tear Test, Storm was diagnosed with Keratoconjunctivitis Sicca or KCS. This is a very commonly encountered condition in certain breeds such as Cocker Spaniels, English Bulldogs, West Highland White Terriers, Pugs, Schnauzers, Pekingese and Lhasa Apsos; however, any breed of dog (including mixed breeds, especially those with bulging eyes) may be affected. The cause of an individual case of KCS rarely is determined, but possible causes may include a hereditary predisposition, immune-mediated gland disease, reaction to certain sulfa-containing drugs, tear gland destruction from an infection with canine parvo virus, and surgical removal of the third eyelid in “cherry eye” syndrome. As with most cases of KCS, why Storm developed KCS remains a mystery.

KCS is commonly misdiagnosed as a chronic bacterial infection of the eye. If a veterinarian does not do a Schirmer Tear Test on the dog, they may continue to put the dog on topical eye antibiotics thinking it is a simple bacterial conjunctivitis. With the antibiotics, the discharge often decreases (usually this is due to the antibiotic drops or ointment helping to lubricate the eye, thus clinical signs begin to resolve); however, when the topical antibiotics are stopped, the discharge reappears. Only by doing a Schirmer Tear Test can KCS be properly diagnosed.

Medical treatment of KCS involves cleansing of the eye of discharge multiple times per day to help decrease the bacterial load to the eye. (Bacteria love that nice warm discharge that collects in the corner of the eyes!) Also there is medication that can be given to these dogs. Artificial tears can be given to the eye to temporarily help lubricate the cornea, however, actually treating the condition will produce the great results. Recently, Schering-Plough Animal Health Company introduced a new ointment for the treatment of KCS called “Opptimmune” which contains a 0.2% level of cyclosporine, a drug which commonly has been known to treat cases of KCS. Cyclosporine was originally designed as a noncytotoxic immunosuppressant used in human medicine to prevent organ transplant rejection. In dogs with KCS, cyclosporine may improve tear production by decreased immune-mediated actions in the tear gland, thus allowing it to function more normally. This new medication is easy to administer than previously used drugs and needs to be applied twice daily.

There is a debate as to whether KCS is actually painful to dogs that have this condition; however, if not treated, it can cause blindness. Dogs with significant amounts of discharge coming from their eyes should always be checked by a veterinarian. Whether the dog is suffering from KCS, a bacterial conjunctivitis or a corneal ulcer, all are important reasons to have them evaluated and treatment started.