Glaucoma is common in both humans and dogs. When pressure fluid inside the eyeball is too high, internal structures can be destroyed. This is glaucoma. The pressure damage is similar to high blood pressure rupturing a blood vessel in the brain, causing blood flooding that damages brain cells — otherwise known as a stroke. Glaucoma renders the affected eye blind and useless in most cases.
What causes glaucoma? The fluid in the eyeball is known as aqueous humor. Drainage issues — the aqueous humor not being able to drain properly from the eye — is the most frequent cause of glaucoma. Whether or not the fluid drains, the eye is constantly producing more aqueous humor. The fluid fills the eyeball until internal structures are crushed or displaced.
There are two types of glaucoma in pets: primary and secondary. Primary glaucoma occurs because an animal has certain physical traits that cause problems. Drainage pores that are two small and narrow ducts can be physical issues that lead to primary glaucoma. Secondary glaucoma means that the disease is caused by another condition, like a wound to the eye.
Certain breeds of dog are more likely than others to have issues with primary glaucoma: beagles, cocker spaniels, and basset hounds are the most common glaucoma sufferers. The disease may not develop until the dog is two or three years old or older. Typically, primary glaucoma develops in one eye, then the other — rarely both eyes at the same time.
Watch for the early signs of glaucoma: pain, a dilated pupil, cloudiness in the cornea, and bloodshot eyes. Your pet may rub at his eye with a paw, or rub his face against furniture and carpets. He may also flutter his eyelids, or squint. The pupil of the affected eye will react very slowly to light — since glaucoma usually only affects one eye at a time, watch for differences in pupil size. By the time you see bloodshot eyes on your pet, major damage has probably already been done.
If treatment is not started within a few days of pressure increase, vision in the affected eye can be completely lost. Glaucoma in pets is a medical emergency! If you suspect that your dog has glaucoma, take your pet to the veterinarian immediately.