Glaucoma in dogs can’t always be prevented, especially when it’s genetic, but you can significantly lower your dog’s risk and protect their vision through regular screening, practical lifestyle changes, and early detection. The key is understanding which dogs are most vulnerable and acting before symptoms become obvious, because by the time glaucoma is visible to the naked eye, permanent damage to the optic nerve may already be underway.
Why Some Dogs Get Glaucoma
Glaucoma happens when fluid inside the eye doesn’t drain properly, causing pressure to build. That pressure damages the optic nerve and, without treatment, leads to blindness. Dogs develop two types: primary glaucoma, which is inherited and affects both eyes over time, and secondary glaucoma, which results from another eye condition like inflammation, lens displacement, or injury.
Primary glaucoma is the type you’re least able to prevent outright, because it’s baked into your dog’s genetics. Secondary glaucoma, on the other hand, is often preventable by managing the underlying problem before pressure starts to climb.
Breeds at Highest Risk
Certain breeds carry a much higher genetic risk. A large-scale study of purebred dogs in North America found the highest glaucoma rates in American Cocker Spaniels (5.52%), Basset Hounds (5.44%), Chow Chows (4.70%), and Shar-Peis (4.40%). Boston Terriers, Wire Fox Terriers, Norwegian Elkhounds, Siberian Huskies, Cairn Terriers, and Miniature Poodles also ranked in the top ten. American Cocker Spaniels, Basset Hounds, Wire Fox Terriers, and Boston Terriers have consistently appeared among the most affected breeds in studies spanning from 1964 to 2002.
Most dogs with inherited glaucoma are first diagnosed between ages 4 and 10. If your dog is one of these breeds, the prevention window is before that age range, not after symptoms appear.
Annual Eye Exams Are the Single Best Prevention
Glaucoma begins with subtle changes that owners almost never catch on their own. The American College of Veterinary Ophthalmologists recommends annual eye exams for dogs of all breeds, specifically because inherited eye diseases can emerge at any age. For high-risk breeds, these exams are essential rather than optional.
During an eye exam, a veterinary ophthalmologist uses a device called a tonometer to measure the pressure inside your dog’s eyes. Normal eye pressure in dogs generally falls between 10 and 25 mmHg. Readings consistently above that range signal a problem. The exam also evaluates the drainage angle inside the eye, which can reveal whether your dog is predisposed to glaucoma before pressure actually rises.
If your dog belongs to a high-risk breed, ask your vet about baseline tonometry by age 3 or 4, then continue annually. Catching elevated pressure early, before vision loss occurs, gives you the widest range of treatment options.
Switch From a Collar to a Harness
This is one of the simplest and most overlooked steps you can take. Research shows that collars increase eye pressure by compressing the jugular veins in the neck, which obstructs fluid drainage from the eyes. A study comparing collars and harnesses found that exercising in a collar raised intraocular pressure in all dogs, regardless of head shape. For flat-faced (brachycephalic) breeds, simply wearing a collar while standing still was enough to increase eye pressure.
Harnesses did not raise eye pressure in any dogs tested, whether they were exercising or stationary. This held true even though dogs tend to pull harder in a harness, generating more overall force. The difference is where that force lands: a harness distributes it across the chest instead of concentrating it on the neck.
If your dog is a high-risk breed, a flat-faced breed, or has already been diagnosed with elevated eye pressure, switching to a well-fitted harness is a no-cost way to remove a source of repeated pressure spikes.
Manage Eye Inflammation Aggressively
Secondary glaucoma often develops as a complication of uveitis, which is inflammation inside the eye. Uveitis can stem from infections, immune disorders, trauma, or breed-specific conditions like golden retriever uveitis. When inflammation goes unchecked, it creates scar tissue and debris that block the eye’s drainage pathways, trapping fluid and raising pressure.
Treating uveitis early and thoroughly is one of the most effective ways to prevent secondary glaucoma. Treatment typically involves anti-inflammatory eye drops and oral medications to bring inflammation under control quickly. For conditions like golden retriever uveitis, the goal of treatment is specifically to reduce inflammation and delay or prevent the onset of glaucoma. Each case requires a tailored approach, but the principle is the same: the faster you suppress inflammation, the less damage it does to the drainage system inside the eye.
If your dog has red, painful, or cloudy eyes, or if they’ve been diagnosed with any form of eye inflammation, follow the prescribed treatment plan closely. Skipping doses or stopping medication early because the eye looks better can allow low-grade inflammation to persist and silently set the stage for glaucoma.
Genetic Testing for Breeding Dogs
Researchers have identified specific genes linked to primary glaucoma in dogs, including ADAMTS10 and ADAMTS17, which are involved in the structural development of the eye’s drainage system. Genetic tests based on these discoveries are becoming available and can identify carriers before they’re bred.
If you’re a breeder working with high-risk breeds, genetic screening is the most powerful long-term prevention tool. Testing breeding stock and avoiding pairings that produce affected puppies can reduce glaucoma prevalence across future generations. If you’re buying a puppy from a high-risk breed, ask the breeder whether the parents have been screened for known glaucoma-associated mutations.
Antioxidant Support for Eye Health
While no supplement has been proven to prevent glaucoma directly, there’s evidence that antioxidants support overall retinal health in dogs. A study published in the Journal of Nutritional Science found that dogs given a daily antioxidant blend (containing lutein, zeaxanthin, beta-carotene, astaxanthin, and vitamins C and E) showed measurably improved retinal function compared to dogs on a standard diet. The supplemented dogs also had less change in their refractive error over time. Importantly, these improvements were seen in healthy dogs with normal eyes, suggesting that antioxidant support benefits the retina even before any disease is present.
A healthy retina won’t stop fluid from building up in the eye, so antioxidants aren’t a substitute for screening or medical treatment. But supporting your dog’s eye health nutritionally may help the retina better withstand the stresses that come with aging or early pressure changes. Look for dog foods or supplements that include lutein, zeaxanthin, and vitamins C and E, and talk to your vet about appropriate amounts for your dog’s size.
Signs to Watch for at Home
Glaucoma often starts with signs so mild that owners dismiss them. The earliest changes include a slightly red eye, occasional squinting, and mild tearing. Owners of dogs with early glaucoma often notice that during nighttime or stressful situations, the whites of the eye become more red, the pupil dilates, and the cornea takes on a slight haze. These episodes may come and go, which makes them easy to write off.
As pressure increases, more consistent signs develop: a cloudy or bluish-white haze across the cornea, a pupil that looks larger than the other eye’s pupil or responds slowly to light, and a pupil that appears irregularly shaped. Advanced glaucoma causes a visibly bulging, bright red eye, loss of appetite, and lethargy from pain.
Get in the habit of looking at your dog’s eyes in good lighting every week or two. Compare both eyes. Asymmetry, whether in pupil size, redness, or clarity, is often the first clue that something is changing in one eye. The earlier you catch these signs and get your dog’s eye pressure checked, the better the chances of preserving vision.