All dogs will have some discharge at the corners of their eyes. It's perfectly normal to need to clean a bit of light gray matter from their eyes once or twice a day. But owners take note: if the color of the discharge is yellow or green, or if buildup appears frequently, you should consider asking your veterinarian to test your dog for dry eye.
Dry eye, or "keratoconjunctivitis sicca" is a common eye problem in dogs, especially bulldogs, cocker spaniels, Shih Tzus, and Lhasa Apsos. Identifying and treating dry eye is important, not only to alleviate your dog's discomfort, but also because left untreated dry eye can lead to serious problems, such as ulcers and blindness.
To understand dry eye, you need to understand why the tear film is important. Dr. Amber Labelle, a veterinary ophthalmologist at the University of Illinois Veterinary Teaching Hospital in Urbana, explains that the tear film on your dog's eye serves several functions: it removes waste, such as dust; helps keep the cornea transparent (the cornea is the clear outer portion of the eye); plays a role in immune function; and brings oxygen and nutrients to the cornea. (Remember, unlike most tissues in the body, the cornea contains no blood vessels to bring oxygen and nutrients because blood vessels would keep the cornea from being transparent.)
"Without a proper tear film, any small scratches or damage to the cornea will not heal well," says Dr. Labelle. "In the long run compensation for a lack of tear film will lead to decreased vision, so it is important to treat your pet's dry eye."
In dogs dry eye typically arises as a result of immune-mediated problems, but the condition has also been associated with diabetes mellitus. Cats rarely get dry eye.
Since your dog cannot tell you that her eyes feel dry and gritty, and not all dogs with dry eye rub at their eyes, eye discharge—excessive goop at the corners of the eye—is the No. 1 sign of the disease.
You might assume that excessive tearing and discharge would be signs of an infection, but in fact bacterial infections, such as pink eye in humans, are uncommon in canine patients, according to Dr. Labelle.
Luckily there is an accurate, quick, and inexpensive way to diagnose dry eye, the Schirmer Tear Test. Most veterinarians are able to perform a Schirmer Tear Test at their clinic. Treating dry eye is also fairly inexpensive and easy. Most dogs respond well to the medications in eye drop form. Treatment will be needed throughout the dog's lifetime.
If you suspect your dog may have dry eye, please seek testing and treatment from your local veterinarian in order to manage the disease and preserve your dog's vision and eye health.
Writer: Andrea Lin
An archive of Pet Columns from the University of Illinois College of Veterinary Medicine is available online at http://vetmed.illinois.edu/petcolumns/. Requests for reprints of this article may be directed to Chris Beuoy, firstname.lastname@example.org.
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