Glaucoma in Dogs

Dogs can get glaucoma just like humans.  Glaucoma is when pressure is put on the eye, causing inadequate drainage of the fluid of the eye.  If the pressure persists, it can damage the optic nerve and even cause blindness.

Unlike humans, most glaucoma is caused by heredity.  Samoyeds, cocker Spaniels, poodles, chow chows, and Siberians are some of the breeds most prone to glaucoma.  Unfortunately, forty percent of dogs with glaucoma will go blind in the first year regardless of treatment.  However, treatment can slow or stop blindness in the other sixty percent of dogs with glaucoma.

Glaucoma can be either primary or secondary.  Primary disease is caused by the eye’s inability to drain through the filtration angles of the eye.  Secondary disease is caused by other causes, such as an eye infection.  Secondary glaucoma is most common in dogs.

Symptoms for primary glaucoma are: high pressure within the eye, blinking of the eye, the eyeball recedes into the head, redness of the blood vessels in the whites of the eye, cloudy appearance at the front of the eye, dilated pupil which does not respond to light, and vision loss.  The long-term, advanced stages of the disease are marked by enlargement of the eyeball, obvious loss of vision, and advanced degeneration within the eye.

Symptoms for secondary glaucoma include some of the same symptoms, such as high pressure within the eye, redness of the blood vessels in the whites of the eyes, and cloudy appearance at the front of the eye.  Other possible symptoms include inflammatory debris visible in the front of the eye, possible constriction of the pupil, possible sticking of the iris to either the cornea or the lens, and the possibility that the edge of the iris circularly sticks to the lens.  In long-term cases, there may be headaches, loss of appetite, and change in attitude, such as less desire to play or interact.  The headaches may be accompanied with head pressing to relieve feelings of pressure in the head.

If you suspect glaucoma in the eye, take your dog to the veterinarian.  He will look at the eye and see if there is a problem.  He may measure the pressure of the eyeball with a special instrument to see if it is too high.  If the symptoms came on suddenly, he may refer you to a veterinary ophthalmologist.  He will do an evaluation of the filtration angles by gonioscopy and measure the anterior angles of the eye.  He will also do an electroretinograph to see if the dog will remain blind despite treatment.  X-rays and ultrasound may also be used to see if there are abnormalities in the eye.

If the glaucoma is caught early enough, the veterinarian will prescribe multiple drugs to treat it.  If the glaucoma has gone on long enough to damage the optic nerve, the drugs will not help.  Usually the eye is removed and the eyelids sewn shut.  The dog will adjust quickly as it was probably blind at this point anyway.  In fact, it will be considerably more comfortable with the offending eye removed.  However, you will have to accompany the dog outside as it will be vulnerable to other animals since it cannot see well or at all.