2016 Pet Guide – Visible Progress
Eye diseases in pets can be inherited or acquired through infection and injury. Knowing the signs can help clear the way to good health.
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Shortly after her vision returned, Abbie chased her first gecko in months, toying with the tiny lizard but not harming it, says her owner, Judy Novak.
“She couldn’t see it before,” says Judy, a retired elementary school teacher who lives in The Villages with her husband, Roger, also retired, and their 8-year-old miniature poodle. Not only had Abbie’s eyes clouded over with thick cataracts, Judy says, the dog’s shy and fearful nature seemed even more pronounced, as her vision deteriorated.
The Novaks adopted Abbie in 2012 through a rescue group in Florida that saved her from an animal shelter in Georgia, after likely abuse, Judy says. Her eye problems surfaced two years later, the most obvious signs bumping into furniture and a gradual change in eye color from brown to almost white.
“I didn’t really notice the clouding right away,” Judy says. “Our primary veterinarian told us it might be cataracts,” but other causes had to be ruled out first. After several visits, the family vet recommended Abbie see Dr. Daniel Priehs, a veterinary eye specialist at Maitland-based Animal Eye Associates, who treats eye diseases in dogs, cats and other domestic animals, along with the occasional bald eagle, penguin and even a flying fox or two.
Priehs told the couple that Abbie’s cataracts were so thick he might not be able to remove them. But after tests showed the retinal nerves at the back of her eyes could withstand surgery, Abbie went under the knife in August 2014. A day later, the elated dog spotted the gecko, the lenses in her eyes totally clear. “She started getting so friendly, even our neighbors noticed,” Judy recalls.
Today, the small poodle remains in training as a therapy dog, visiting local residents at memory centers and assisted living facilities to cheer them up. “She’s totally comfortable in her new role,” Judy says, “She wants to meet everybody.”
Abbie’s success story is a testament to advances in veterinary eye care that rival those in human medicine, experts say. Some of the many eye diseases seen in our pets, especially in dogs, are inherited, they say, although most are acquired —the result of trauma, infections, nutritional deficiencies and metabolic disorders, such as diabetes.
“Dogs and cats seem to get all the same eye diseases as humans, although we see them far more in dogs than cats,” says Dr. Brady Beale, a clinical instructor at the University of Pennsylvania Hospital in Philadelphia, and like Priehs, a veterinary ophthalmologist. “Some of these diseases merely cause discomfort, but others cause considerable pain and even blindness.”
The two most common eye diseases passed down from one canine generation to another are cataracts and glaucoma, a vision-threatening pressure buildup inside the eyes, Beale and others agree. Some dog breeds appear especially vulnerable to these inherited eye problems, while the average mixed-breed cat rarely develops them, Beale says, tending toward injuries in the cornea, the clear surface at the front of the eyes, where viral infections take much of the blame.
In the purebred dog population, the American College of Veterinary Ophthalmologists lists at highest genetic risk for cataracts: Cocker Spaniels, Bichons, Arctic breeds, poodles and terriers, among others. In glaucoma, genes play a major role in many of these same breeds, but the low-slung Bassett Hound also makes the list as one of the more susceptible. Roughly half of these dogs inherit a structural defect in their drainage angle, veterinarians say, which clogs the eye like a stopped-up sink, setting the stage for later disease.
“What we recommend is that purebred dogs get certified by the Orthopedic Foundation for Animals (offa.org) to make sure their eye pathways are clear,” Beale says. “Breeders and owners alike want to know whether parents are passing on one of these diseases.”
Founded more than 40 years ago, the OFA in Columbia, Missouri, began as a dog-oriented organization, charting the genetic roots of hip dysplasia, but now tracks the hereditary role of diseases in all companion pets. Its mission: “the promotion of the health and welfare of companion animals through a reduction in the incidence of genetic disease.”
But, should eye problems develop after purchasing a pet, Brady says, “Do I think owners should rush off to an ophthalmologist? No. Go to the family vet first for a checkup.”
Early signs of eye diseases often show up as obvious discomfort in both dogs and cats, according to veterinarians: redness, gunky discharge from one or both eyes, frequent squinting and cloudiness in the cornea or lens.
Pinpointing the cause can be tricky, though. “We’re a lot like pediatric ophthalmologists,” Priehs says. Just as young children lack words to describe what’s bothering them, he says, so too “your pets can’t tell you what’s wrong with their voice. But they can tell you with their behavior.”
In glaucoma, for example, behavioral cues may include unusual aggressiveness, or its opposite, extreme lethargy, as pressure builds inside the eyes.
Unlike human eyes, where glaucoma may take years to develop, Priehs says, dogs can develop these sight-robbing conditions quickly. His own dog, Pickles, a French bulldog predisposed to glaucoma, saw such a rapid spike in fluid pressure, he says, he performed emergency laser surgery to save her vision.
Cataracts also develop more quickly in dogs than in people and at much younger ages, Priehs says. The majority of cataracts he sees in his practice occur in dogs as young as 10 weeks old, which he treats with a laser-type surgery, virtually identical to that used in humans. Caught early, he says, cataract removal can reduce eye inflammation later on, a major contributor to glaucoma, second only to anatomical abnormalities.
Yet another of the eye diseases veterinarians most frequently confront is dry eye, particularly in short-nosed breeds, such as terriers and bulldogs.
“Dry eye can be a major problem,” says Dr. Caryn Plummer, a veterinary ophthalmologist at the University of Florida’s College of Veterinary Medicine in Gainesville. “Not only is dry eye uncomfortable, but it causes inflammation and can lead to corneal ulcers,” or unprotected wounds on the surface of the eyes. And, in the worst cases, it can lead to progressive loss of vision, she says.
Both environmental and genetics are thought to play likely roles in the condition’s development. Once present, pets no longer make enough liquid for tear production, Plummer says, or they make enough, but it’s of poor quality.
She recommends checking for redness in the mucous membrane that lines the inner surface of a pet’s eyelids, or unusual changes in discharges.
Cats also get dry eyes, Plummer says, though their corneal wounds arise mostly from viral infections, such as the feline herpesvirus, present in newborn litters, or sometimes caused by nasty dust-ups with other cats.
Ultimately, what determines the course of treatment in either dogs or cats is the depth and location of a corneal injury, she says: some need only topical medications to control infection; others require corneal grafts to keep the eye from collapsing.
“In animals, these procedures tend to be more dramatic than in humans,” adds Penn’s Beale. “We treat them to save vision, not just to patch a leak.”
As to the most common cause of corneal injuries she sees? “It’s usually the puppy who meets the family pet for the very first time,” he says.
Whether eye diseases in pets are on the rise is unclear given limited data. But, Priehs suggests, more consumers are seeking specialized treatments due to increasing genetic problems not related to breeders, but to puppy mills.
“Breeders are quite diligent,” he says, citing a decrease in inherited eyelid problems, once the bane of too many purebreds. Also, he says, pet owners treat their dogs and cats today as family. “They’re more attuned to health problems,” and know when to seek specialty care.
Not surprisingly, however, that care comes with a high price tag.
The Novaks spent $4,000 on Abbie’s cataract surgery alone; the national average is typically $2,000 per eye. While the couple lacked pet insurance, insurance coverage varies, veterinarians caution, with some insurers covering part of the cost, while others deny claims as pre-existing conditions.
For the Novaks, there’s little doubt the expense has been worthwhile, as Abbie joyfully reconnects with the world around her. “She looks wonderful,” Judy says. “She has back her beautiful eyes now.”