Glaucoma

Glaucoma is high pressure inside the eye. It is painful, it destroys the retina and optic nerve quickly, and it is more common in purebred dogs than in any other species, with primary glaucoma affecting close to 1 percent of purebreds in North America¹. In teaching-hospital records the highest breed rates were the American Cocker Spaniel, Basset Hound, Chow Chow, Chinese Shar-Pei, Boston Terrier and Siberian Husky². Beagles and Norwegian Elkhounds have an inherited open-angle form¹.

Early signs are subtle, which is why the Merck Veterinary Manual advises pressure checks at annual examinations for high-risk breeds¹. An acute attack looks like a red, cloudy, bulging or squinting eye, a dilated pupil, and a dog that is suddenly quiet or off its food from pain. That is an emergency: vision can be lost within a day or two. Ask the clinic to see the dog that day.

Dogs that lose one eye to glaucoma often develop it in the other, so ongoing pressure checks matter after the first episode¹.

This is general information, not a diagnosis. Your vet knows your dog.

Sources

1. Glaucoma in Animals. Merck Veterinary Manual. Accessed 2026-09-22.
2. Prevalence of the breed-related glaucomas in pure-bred dogs in North America (Gelatt KN, MacKay EO). Veterinary Ophthalmology 7(2):97-111, 2004 (peer reviewed). Accessed 2026-09-22.