Keratoconjunctivitis Sicca (KCS)

Dear Dr. Jody: Our eight year old pug, “Raisin”, has recently started showing unusual symptoms in his eyes. Both eyes have a lot of yellowish discharge, and he is pawing at them. The surface of his right eye also seems to be turning brown. What is going on with “Raisin”? 

While it is impossible to determine exactly what might be going on with little Raisin’s eyes without a thorough ophthalmic exam, it is worth considering a common ailment of pugs called keratoconjuncitivitis sicca (KCS). 

KCS is an ocular condition characterized by inadequate tear production. Tears are composed of several different types of fluid. In KCS, the tear glands on the margins of the eyelids and of the third eyelid dramatically decrease their output of the salt-water portion of the tears. The eye becomes dry and irritated, and, as a result, the glands overproduce the goopy mucous part of the tears. This results in a buildup of excessive amounts of yellow discharge. The dog may also squint and paw at his eyes as if they are uncomfortable. KCS is a very painful condition. If left untreated, it can lead to permanent changes in the appearance and function of the eye. 

There are several potential causes of KCS. In many breeds, KCS can be immune-mediated. This means that the immune system mistakenly begins attacking the cells of the glands that produce the tears, thereby shutting down their tear output. Sometimes, KCS can be related to nerve damage. Because tear production is controlled by a branch of the facial nerve that runs along the cheekbone, damage to this area can impair the production of tears. Thirdly, there are some medications that can have temporary or permanent negative effects on tear production. 

Your veterinarian will perform a Schirmer Tear Test (STT) on Raisin. This test measures his tear production with the aid of a tiny piece of paper tucked under the lower eyelid. Your vet measures how far down the piece of paper Raisin’s tears will wick in 60 seconds. She will also perform a fluorecein stain test to ensure that there are no corneal ulcers or erosions secondary to the chronic dryness and irritation. 

The good news is that KCS is manageable with medication. Unfortunately, in most cases, KCS requires lifelong treatment to provide adequate relief of symptoms. Several different medications are available. Topical medications such as cyclosporine and tacrolimus can provide significant relief to Raisin’s poor dry little eyes, and help minimize the risk of painful corneal ulceration or scarring that can impair his vision over time. 

Please contact your veterinarian to set up an ophthalmic exam if you are concerned that your pet’s eyes may not be unhealthy or uncomfortable.