Understanding Glaucoma in Dogs

Glaucoma in dogs is an eye disease that often goes undetected until after a dog has lost vision in one or both eyes. With several breeds being predisposed to the disease, it is important to know if glaucoma is common in your dog's breed and to keep a watch for the symptoms as glaucoma can make permanent vision loss a reality in a matter of a few hours.

Glaucoma Defined

Glaucoma is increased eye pressure inside the eye. This is caused by the fluids inside the eye building up because the drain system is clogged. As the pressure builds, the fluid puts pressure on the optic nerve and cuts off the blood supply to the retina. This can cause a permanent loss of vision if the condition is not controlled. Unfortunately, the disease often goes undiscovered until the dog has permanently lost vision in one eye and is experiencing difficulty in the second eye.

There are 2 types of glaucoma.

Primary glaucoma is an inherited condition and is common in many breeds including American Cocker Spaniels, Basset Hounds, Chow Chows, Elkhounds, Huskies, Labrador Retrievers and Shar Peis. Primary glaucoma will most typically begin in one eye, but will eventually involve the other eye as well. Glaucoma may progress quite rapidly, within a matter of hours, so once a problem is detected it is imperative to seek treatment immediately.

Secondary glaucoma is caused when other eye diseases such as mature cataracts or inflammation inside the eye reduce the drainage from the eye.

Glaucoma Diagnosis

In order to diagnose glaucoma, the veterinary ophthalmologist must conduct a tonometry test that measures the dog's intraocular pressure (IOP). If his IOP reading is between 10 and 20 mmHg, the pressure is normal. While anything above that is considered high, dogs often present with readings of 45 to 60 mmHg, increasing the pain in the eye.

Once glaucoma is confirmed, the veterinary ophthalmologist will conduct several other tests to determine whether it is primary or secondary glaucoma, what the visual prognosis is for your dog's eye(s) and what course of treatment is recommended.

Symptoms of Glaucoma

In most instances, glaucoma's presence is difficult to detect for the untrained eye. Your dog's eye may appear red or bloodshot and vision loss is common. The eye may also appear distended or enlarged. If the eye has reached this stage, vision loss is often permanent.

Treatment for Glaucoma

There is no standard method of treatment for glaucoma. Depending upon the type of glaucoma (primary or secondary) and whether the eye still has sight, the recommendation can be very different. Medical options include drops or pills to reduce the IOP and surgical options start with duct implants to allow drainage from the eye as well as other surgical options for a non-sighted eye.

Glaucoma can have a tremendous impact upon your dog's vision. It is important to know if your dog is predisposed to glaucoma so you can watch for signs of change in his vision, whether caused by heredity or another eye disease. By keeping these things in mind, you can help prolong your dog's vision through quick medical treatment should glaucoma arise.