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Wanted: 300 Pugs to Help Find Answers to Perplexing Eye Problem

Published December 19, 2011
An archive of Pet Columns from the University of Illinois College of Veterinary Medicine is available online at Requests for reprints of this article may be directed to Chris Beuoy,

With their round faces and sorrowful gaze, pugs capture the hearts of many. Luckily for pugs, one such enthusiast is setting out to make a major contribution to pug health, and she's seeking assistance from 300 of these little charmers as she tackles the first phase of her work.

Dr. Amber Labelle, a veterinary ophthalmologist at the University of Illinois Veterinary Teaching Hospital in Urbana, says she is "owned by a five-year-old pug named Dexter."

She also says "most of the pugs we see at our hospital are afflicted with pigmentary keratitis, a condition in which a brown pigment forms on the surface of the cornea, the normally clear surface of the eye that allows light to enter the eye."

This disease can eventually cause blindness, if the pigmentation completely blocks light from entering the eye. The "keratitis" part of pigmentary keratitis refers to inflammation of the cornea, another aspect of this disease, which creates discomfort in the eyes of these animals.

Unfortunately, very little is known about pigmentary keratitis. "There was one academic paper published on pigmentation of the cornea in 1966, and that's it," says Dr. Labelle. "This is why there is such a huge need to learn more about the disease."

Clinical examination of affected pugs has shown that the pigment often begins to develop at the inner corner of the dog's eye, and slowly spreads closer to the center of the cornea. The amount of pigment in the cornea can be minimal or can block the entire cornea. Once pigment has settled into the cells of the cornea, there is no treatment that will completely reverse the effects.

Current treatment is aimed at preventing the spread of pigment across the surface of the eye using one of two prescription eye drops: cyclosporine A and tacrolimus. These two medications are commonly used for other eye diseases because they change the way the immune system behaves on the surface of the eye. However, it is not known why these medications are effective against pigmentary keratitis.

"In most cases, these medications are fairly effective at preventing the spread of pigment, but they must be used daily for the rest of the dog's life," Dr. Labelle says.

Pugs also tend to have other eye abnormalities, such as abnormally positioned eyelids or eyelids that do not close completely, which may lead to irritation of the cornea. These issues are suspected to contribute to the progression of pigmentary keratitis, so Dr. Labelle recommends treating those problems as well to decrease the severity of the disease. One way to prevent this irritation is to perform a surgical procedure that corrects the way the eyelids sit on the surface of the eye, decreasing the amount of irritation that the eyelid causes.

"My goal is to put a stop to pigmentary keratitis," says Dr. Labelle. Over the next few months, she will examine the eyes of 300 pugs as part of a study of the disease. Each dog will have every aspect of its eyes inspected, ranging from the shape of the head to detailed examination of the surface of the eye. The results of those examinations will be analyzed to determine possible risk factors for pigmentary keratitis.

If you have a pug and would like to participate in the project, you can schedule an appointment to meet Dr. Labelle at the Milwaukee Pug Fest in May 2012. For more information on pigmentary keratitis and Dr. Labelle's study, visit the "Pigmentary Keratitis in Pugs" blog:

Much work lies ahead to save the vision of pugs affected by pigmentary keratitis, and Dr. Labelle is determined to achieve that goal. Meanwhile, pug owners should know that early detection and treatment are essential to prevent the progression of this blinding disease.

An archive of Pet Columns from the University of Illinois College of Veterinary Medicine is available online at Requests for reprints of this article may be directed to Chris Beuoy,

Veterinary Extension/Office of Public Engagement
University of Illinois College of Veterinary Medicine