by Kerry McKinney, DVM
Glaucoma is a disease that damages the optic nerve and retina, leading to blindness—usually via a painful increase in pressure within the eye. Managing glaucoma successfully depends on finding it early.
Glaucoma occurs as a primary genetically influenced disease in some breeds. (Please see below for a list of predisposed breeds of cats and dogs.) Pressure inside the eye can also increase secondarily in response to other ocular disease and some topical and oral medications. Secondary glaucoma can develop in any breed of dog or cat and is actually both the most commonly diagnosed AND under-diagnosed form of glaucoma.
Our pets often don't come right out and tell us they have the equivalent of a constant migraine headache, but they may be less interested in play and meal times. You may notice the later stages of glaucoma which can include a red, cloudy, or bulging eye—which generally means vision in that eye has already been lost. Pets also won't tell you they've gone blind in one eye because they compensate so well with the other.
You can't tell just by looking that your pet's intraocular pressure (IOP) is increasing, and your pet may not "say" anything until it's too late. Fortunately, your veterinarian can easily measure IOP as a glaucoma screening test during a routine wellness visit. Establishing a baseline IOP and regular annual or semi-annual monitoring can help identify a trend and allow earlier intervention to preserve vision and comfort. Increasing IOP or a large difference between eyes increases concern for developing glaucoma and referral to a veterinary ophthalmologist for confirmation may be recommended.
In addition to the breeds noted below, pets with a history of chronic inflammation, cancer, systemic hypertension, cataracts, lens injury, trauma and those receiving chronic topical or oral corticosteroids (prednisone, prednisolone, dexamethasone) are candidates for regular glaucoma screening.
Feline Breeds Predisposed to Developing Primary Glaucoma
Burmese, Persian, Siamese
Canine Breeds Predisposed to Developing Primary Glaucoma
Afghan, Alaskan Malamute, Basset Hound, Beagle, Border Collie, Bouvier des Flanders, Cardigan Welsh Corgi, Chihuahua, Chow Chow, Cocker Spaniel, Dachshund, Dalmatian, Greyhound, Great Dane, Italian Greyhound,
Maltese, Miniature Pinscher, Norwegian Elkhound, Pembroke Welsh Corgi, Poodle, Saluki, Samoyed, Giant Schnauzer, Shar Pei, Shiba Inu, Shih Tzu, Siberian Husky, Springer Spaniels (English & Welsh), Whippet,
Terriers (Boston, Cairn, Dandie Dinmont, Jack Russell, Manchester, Norfolk, Norwich, Scottish, Sealyham, Smooth & Wire-haired Fox, Tibetan, Welsh, West Highland White)