Glaucoma in Dogs
While not one of the most common conditions in dogs, glaucoma can ultimately lead to blindness. However, an early diagnosis coupled with the proper treatment affords concerned owners a fighting chance at saving their cherished canine companions’ sight.
What then, IS glaucoma?
Glaucoma is a painful disorder that occurs as a result of an abnormal increase in eye pressure (IOP or intraocular pressure). Although it can be caused by genetic factors, it’s more commonly linked to such underlying conditions as inflammation, tumors, trauma or changes in the lens that can lead to a buildup of fluid inside the eye.
Under normal conditions, clear fluid (aqueous humor) is produced within your dog’s eye. This fluid not only helps the eye maintain its shape, but it also delivers nutrients and removes metabolites during the circulation process.
In healthy eyes, the amount of fluid that’s produced is balanced by an equal amount of fluid exiting the eyes. But should there be an increase in the amount of fluid that’s being produced or if something obstructs its ability to drain normally, the liquid will build up and result in increased eye pressure.
This increase in pressure can damage the retina (the lining at the back of the eye that detects light) as well as the optic nerve, which carries impulses to the brain. If the pressure remains high for between 24 and 72 hours, it can cause permanent blindness in your dog.
Glaucoma may affect one or both eyes, and the symptoms can vary, depending on the amount of pressure, the underlying cause and how long the pressure has been elevated.
Signs that your dog has glaucoma include:
Increased blinking
Dilated pupil(s)
Enlargement of the affected eye(s)
A clear to cloudy discharge from one or both eyes
Redness and swelling of the vessels in the sclera (the white portion of the eye)
Cloudiness of the cornea (the clear outer layer of the eye)
Bumping into objects
Depression
Loss of appetite
In order to diagnose glaucoma, your vet will perform a thorough examination of your dog’s eyes and use a veterinary tonometer (a small, thin instrument resembling a thermometer) to measure the pressure inside his eyes. While elevated pressure is a sign that glaucoma is present, more sophisticated testing can be done – your vet will usually refer you to a veterinary ophthalmologist for this -- to determine the cause behind the change in pressure and prescribe the appropriate course of action to treat it. The goal: to reduce the pressure, control the pain and preserve your dog’s sight.
Depending on the underlying cause of his condition, your dog’s treatment can include topical eye medications, oral medications and surgery, since, in severe cases, the affected eye may have to be removed. And because many dogs with glaucoma in one eye will eventually develop glaucoma in the other eye, your vet may prescribe additional medications to delay its onset, schedule regular check-ups, and instruct you to watch for subtle changes in your pup’s eyes and behavior.
But take heart. Dogs who lose their sight usually adapt to their situation admirably and continue to lead happy, healthy and loving lives.
Article by Nomi Berger. Nomi is the bestselling author of seven novels, one work of non-fiction, two volumes of poetry, and hundreds of articles. She lives in Toronto, Ontario, Canada with her adopted Maltese, Mini, and has been writing as a volunteer for animal rescue groups in Canada and the U.S.A. since 2013.