By John Gilpatrick
A dog’s nose often guides his actions and movements, but his eyes are just as important. Maintaining dog eye health is critical to having a happy and healthy pet.
Cataracts, therefore, are something dog owners should be able to spot and understand.
“A cataract is an opacity, or imperfection, in the lens of the eye,” says Dr. Matthew Fife, owner of the Veterinary Ophthalmology Center in Orlando, Florida.
Like the lens of a camera, Fife says, the lens of the eye focuses light and should be crystal clear. When a dog has a cataract, it obscures the vision. The cataract may be the size of a pinpoint, which most dogs (and people) can’t notice, but a cataract may also grow to the size of the entire lens, which can cause blindness.
Learn more about how canine cataracts develop and what you can do to help your dog if he has them.
How Do Cataracts in Dogs Develop?
“The lens is comprised of specialized cells that produce fibers made of protein,” Fife says. “Cataracts occur when the cells or protein fibers are damaged.”
Diabetes in dogs can cause cataracts to develop, says Fife. “High blood sugar levels alter the metabolism of the cells in the lens and can cause very rapid onset cataracts,” he explains.
The most common reason cataracts develop in humans is damage from exposure to ultraviolet light. While Fife says UV light can contribute to cataracts in dogs, it’s not the most common cause. Cataracts that happen as the result of UV light usually develop later in a dog’s life.
Another cause of cataracts in dogs comes down to genetics.
“Hereditary cataracts occur quite commonly in certain purebred dogs,” Fife says. “Breeds like Poodles, Cocker Spaniels, Siberian Huskies, and Yorkshire Terriers, among many others, are affected by hereditary cataracts.”
Hereditary cataracts, Fife says, tend to form in dogs at a young age—between 1 and 5 years old.
Can Dogs with Cataracts Still See?
Most of the time, yes, dogs with cataracts can still see.
Dr. Gwen Sila, a veterinary opthamologist for BluePearl Veterinary Partners in Michigan, categorizes canine cataracts in three ways.
“Incipient cataracts cover less than 15 percent of the surface area of the lens,” she says. Many dogs won’t notice these, and they’ll rarely undergo surgery to remove the cataract at this stage.
On the other hand, mature cataracts are those that cover the entire lens. Sila says dogs with mature cataracts can only see changes in light. She recommends that dogs with mature cataracts undergo cataract surgery to remove them.
In between these two—from 15 percent all the way to 99 percent—are immature cataracts, which Sila says can be something of a gray area. “We usually begin to see significant vision deficits with cataracts that cover 75 percent of the lens, but the degree to which it impacts the dog varies.”
Do Cataracts Hurt Dogs?
Gila says a dog might experience disorientation or confusion if a cataract develops quickly, but generally speaking, the cataract itself does not hurt.
That said, inflammation typically accompanies cataracts, which can be painful or at least uncomfortable. “When the protein structure in a lens changes, the body sees that as a foreign substance,” Gila says. “This is what causes the inflammation, and down the road, it can also lead to glaucoma, which is very, very painful.”
For that reason, Gila recommends that pet owners looking to treat immature cataracts in dogs start their pet on a regimen of anti-inflammatory dog cataract eye drops. These drops will likely need to be used throughout the dog’s life.
There is currently no eye drop on the market that will resolve a mature cataract, notes Dr. Katie Grzyb, medical director at One Love Animal Hospital in Brooklyn, New York. “There are some beliefs that certain antioxidant eye drops can slow down the progression of small cataracts just by improving the overall health of the eye,” she says, “but they will not dissolve the cataract.”
How to Tell If Your Dog Has a Cataract
To identify cataracts in dogs, just look for whiteness in the pupils.
Mature and even some immature cataracts are easy to spot due to their cloudy nature, Gila says. It’s when you get into the incipient cataracts that you need to look for other clues.
“If your dog has difficulty catching food, if he’s sniffing for treats rather than seeing them, or if he’s not able to fetch or retrieve as well as usual, he might have cataracts,” she says.
Most of the time, she adds, cataracts in dogs will occur over time, but with diabetic cataracts, you may see your dog start bumping into things overnight.
Cataracts in Dogs: Treatment and Prevention
Cataracts won’t go away on their own, says Gila, they need to be removed surgically. If you see or suspect that your dog has a cataract, consult your vet or a veterinary opthamologist to discuss whether surgery is right for your dog.
“Because we can see things pop back up after surgery, this option requires a lifelong commitment from the owner,” Gila says.
Immediately after cataract surgery, your vet will likely start your dog on a routine of anti-inflammatory cataract eye drops. After the procedure, the drops will ramp up for about four to six months. You’ll also likely need to schedule regular vet appointments to recheck your dog’s eye. After that period of time, Gila says you’ll still need to give your dog the eye drops, and regular checkups should continue.
Because so many canine cataracts are hereditary, there’s not much an owner can do to prevent them, but Gila says a high-quality diet with an antioxidant supplement may help. For example, omega-3 fatty acids, such as those found in fish oil, promote eye health, as well as heart, brain, joint, and skin health, Grzyb says. Consult with your vet or a veterinary nutritionist to find out what is appropriate for your dog.
You can also help prevent cataracts in dogs by blocking harmful UV rays. This includes making sure your dog has plenty of shade while outdoors, says Gila.