Cataracts in dogs may sometimes make a dog’s vision cloudy or steal it completely. But, as you will see from this Labrador’s story, that doesn’t have to keep a dog from having a wonderful life. Integrative veterinarian Dr. Julie Buzby explains what a cataract is, and discusses the causes, stages, symptoms, treatment, complications, and how to help your dog adjust to being blind.
One of my veterinary colleagues was recently telling me about her parents’ Labrador mix, Clark. Although he has since passed away, she said she loves to tell his story to her clients to remind them that cataracts (or other causes of blindness) don’t have to keep a dog from enjoying life to the fullest.
Clark had a rough start to life. He and almost 400 other dogs were found living in deplorable conditions in hog barns. Shortly after the dogs were rescued, one of the vets who had volunteered her time to help care for the sick dogs was walking between a row of dogs in crates.
Suddenly, the unmistakable sound of a tail thumping against the side of a cage caught her attention. When she bent down to see the dog inside, there was Clark. He was completely blind due to advanced cataracts but just as sweet and happy as could be.
She never intended to take a dog home with her that day. But there was something special about Clark. He spent the next month learning how to be an indoor dog and navigate the world from one of her friends, who happens to be a vet tech and dog foster mom extraordinaire.
Then the time came for this lovable rescue dog to find his forever family, which is where my colleague’s family comes in. For the next five years, Clark had a fantastic life. More on that after we get into the nitty gritty on cataracts in dogs.
What are cataracts in dogs?
To understand cataracts, it helps to understand how the eye works. Inside each eye is a clear disc called the lens. Much like a lens in a camera, it focuses light onto the retina. Specialized cells in the retina translate the light into a nerve signal which travels to the brain. The brain then converts the signal into the image that we perceive.
But what do you think would happen if the lens suddenly became cloudy or opaque? Imagine what happens if you leave the lens cap on your camera or the lens becomes covered in specks of dirt. This is sort of like what happens in cataracts in dogs.
You see, cataracts cause the formerly clear lens to become progressively more opaque. Now the beam of light carrying the image information can’t get through the lens properly to hit the retina. This reduces or eliminates a dog’s ability to see out of that eye.
What causes cataracts in dogs?
There are a variety of reasons that a cataract may form. Broadly speaking, the causes are divided into primary causes (i.e. those that happen independent of any other cause) and secondary causes (i.e. those that occur as a direct result of another process).
Primary causes of cataracts
- Old age—When dogs age, they may not be able to restore old or damaged lens protein fibers as quickly as they used to. This may lead to cataract development.
- Genetics— Cataracts may be hereditary in over 150 dog breeds such as Cocker Spaniels, Boston Terriers, Australian Shepherds, French Bulldogs, and Labrador Retrievers. Genetic testing is available for some breeds to identify carriers of the genes linked to hereditary cataract formation.
Secondary causes of cataracts
- Eye injury—Damage to lens fibers from trauma, radiation, toxins, drugs, nutritional deficiencies, or other situations may lead to cataract formation.
- Diabetes mellitus— This is the second most common cause of cataracts in dogs. Diabetic dogs may have excess levels of glucose in their blood. When glucose gets into the lens, an enzyme converts the glucose into sorbitol. This large molecule irreversibly pulls water into the lens. As water enters the lens it damages the lens fibers and leads to cataract formation. In some cases diabetic cataracts can show up as soon as 24 hours from the time of diagnosis. Other times they occur later on in the disease process.
What are the stages of cataracts in dogs?
There are four different stages for canine cataracts. Cataracts will sometimes progress through all four stages. Other times they will stop at one particular stage.
- Incipient cataract—This type of cataract involves only 10 to 15% of the lens. It typically doesn’t cause any vision loss.
- Immature cataract—When the cataract takes up greater than 15% of the lens, it is classified as an immature cataract. Vision may be mildly or moderately impacted.
- Mature cataract—This type of cataract affects the entire lens. Vision loss is near complete, though the dog may be able to see some shadows if the retina is healthy.
- Hypermature cataract—Sometimes the body will try to reabsorb a mature cataract. As the lens of the eye liquifies, it shrinks and leaves behind a wrinkled lens capsule. If the retina is healthy, some dogs can regain some vision in the affected eye. It is possible for immature cataracts to skip the mature phase and go straight to the hypermature stage.
What do cataracts look like in dogs?
Depending on the cause of the cataracts, they may affect one or both eyes. Most incipient or early immature cataracts are difficult to see when just looking at your dog’s eye.
Affected dogs might not show any signs at all. As a result, many dog parents don’t realize a cataract is present until their veterinarian finds it on an eye exam.
As a cataract progresses to late immature, mature or hypermature, it is much easier to see. Typically, you will notice that your dog’s eye looks cloudy or white in the area right behind the pupil where the lens sits.
This is especially evident if you are in a dark room where your dog’s pupil will naturally dilate. If you then use a penlight or flashlight to look at your dog’s eyes, you may see the cataract. As your dog’s vision decreases, you may also notice your dog bumping into things or acting tentative in new situations.
Cataracts vs. nuclear sclerosis
It is important to mention dog parents may understandably confuse nuclear sclerosis in dogs with cataracts. Nuclear sclerosis (i.e. lenticular sclerosis) is a normal age-related change caused by hardened lens fibers that have become less flexible.
With nuclear sclerosis, the lens is a greyish-blue color but light passes through it normally. This means that vision should be virtually unchanged, although some dogs may be a bit farsighted. Your vet can distinguish between the two conditions using an ophthalmoscope.
How will my vet diagnose cataracts in dogs?
Anytime you notice something is off with your dog’s eyes, it is always best to visit your vet. As part of a comprehensive eye exam, your vet will evaluate your dog’s vision. Sometimes this involves watching your dog attempt to navigate a maze of chairs or other objects in the light and in the dark.
Other times he or she may check your dog’s menace response. This involves covering one of your dog’s eyes and rapidly moving a fist towards the open eye as though to hit the dog (but stopping several inches away). If the dog can see, he or she should blink or pull the head away as the vet’s fist comes close to the eye.
The vet will also view the lens and other internal eye structures using an ophthalmoscope in a dark room. When the lens is illuminated and magnified by the ophthalmoscope, it is easy for the vet to visualize the cataract (if present). With incipient or early immature cataracts, the vet may still be able to see through the lens to evaluate the retina. However, this isn’t possible with a mature or hypermature cataract.
As the lens is illuminated, the vet can also distinguish between nuclear sclerosis (no opacity to lens so light passes through normally) and cataract (opacity that keeps some or all light from going through the lens).
What is the treatment for cataracts?
After diagnosing your dog with cataracts, your vet will discuss the potential treatment options. Sometimes this will simply involve monitoring and more frequent eye exams if the cataract is incipient or early immature. In other cases, the vet may recommend an evaluation with a board-certified veterinary ophthalmologist to see if your dog is a candidate for cataract surgery.
Cataract surgery for dogs
This is the treatment of choice for dogs with inherited or diabetic cataracts. Since it requires specialized training and equipment, only board-certified veterinary ophthalmologists perform cataract surgery. The good news is that it has a high likelihood of successfully restoring vision as long as the rest of the eye is healthy.
Prior to surgery, the veterinary ophthalmologist will perform some tests to ensure that the retina is functioning correctly. This is critical because if the retina is nonfunctional, the dog will remain blind even after cataract removal. It is also important that diabetes is under control (if present) and there isn’t any ongoing eye inflammation or retinal disease at the time of surgery.
A dog must undergo general anesthesia for cataract surgery. So if you are wondering, “Is my dog too old for anesthesia?” or “Is my dog too old for surgery?” please discuss the pros and cons with your veterinarian.
The surgical procedure
Once the dog is anesthetized for cataract surgery in dogs, the veterinary ophthalmologist will make a small incision into the eye. Then he or she will use a special tool to break the diseased lens into small fragments. The veterinary ophthalmologist will continue this process until he or she has surgically removed all lens fragments. This process is called phacoemulsification. Afterward, the veterinary ophthalmologist will implant an artificial lens. This step is important because without a lens to focus light, the dog’s vision would be very blurry.
After surgery, the ophthalmologist will send home a series of anti-inflammatory and antibiotic topical eye medications. It is important to give these medications as directed because they help reduce pain and prevent infection. Your dog will also be wearing an E-collar to help protect the eyes. While I know it isn’t fun for your dog to have to wear a “cone of shame,” keeping it on is critical to your dog’s recovery and the success of the surgery.
Cataract treatment without surgery
While cataract surgery can miraculously restore sight, it isn’t always an option for all dogs. Some dogs may not be a candidate due to underlying health problems or a non-functional retina. In other cases, cataract surgery is cost prohibitive for dog parents since it is often several thousand dollars. Unfortunately, medical treatment can’t cure cataracts, but it can often keep your dog’s eyes comfortable if secondary problems occur.
Management of cataract complications
Some dogs with cataracts will eventually develop glaucoma (i.e. increased pressure within the eye). Others may have episodes of lens-induced uveitis. This is inflammation of the inside of the eye which occurs when lens proteins leak out of the lens and trigger an immune response.
Both of these conditions may cause pain and discomfort. Some ophthalmologists believe that these eye issues can cause headaches in dogs, though this is difficult to gauge objectively. After all, you can’t ask your doggie whether or not he or she has a headache!
If either of these conditions develop, your veterinarian or the veterinary ophthalmologists may prescribe certain medications. Topical anti-inflammatory meds can relieve pain and discomfort due to uveitis. Dogs with glaucoma often benefit from glaucoma medications to regulate the eye pressures. Because of the risk of glaucoma, ophthalmologists recommend eye pressure checks every four to six months when cataracts are present.
If any of these cataract complications do not respond to medical therapy and cataract surgery is also not an option, your veterinarian may recommend enucleation surgery. This procedure involves removing the eyeball and its surrounding tissues. While the idea of having a dog who is missing one or both eyes may be difficult to stomach, enucleation often offers your dog permanent relief from eye pain.
Dog parents often remark about how their dog is like a new dog after the enucleation. Plus, most of the time the dog is already blind from cataracts prior to surgery so it doesn’t change his or her ability to get around. It is much less expensive than cataract surgery and can greatly improve quality of life for a dog who is in constant pain from his or her eyes.
What about eye drops for cataracts?
The internet is full of ads for eye drops that claim to dissolve cataracts. However, as of the time of this writing, there are no eye drops or treatments that will definitively treat cataracts or will prevent them from forming. There is some evidence to show that topical aldose reductase inhibitors (ARIs) can delay or prevent diabetic cataracts from developing, but this product is not commercially available. So please don’t get fooled into spending money on any over-the-counter drops that supposedly dissolve or prevent cataracts.
How can I help my dog who has cataracts?
Cataracts will cause visual impairment because they block the passage of light through the eye. These six tips can help you keep your blind dog safe, happy, and confident:
1. Provide a safe and familiar environment
Visually impaired dogs may bump into things or be uncertain in unfamiliar locations. It is important to keep his or her surroundings as familiar as possible and avoid the impulse to rearrange the furniture. That way he or she can remember where to step and what to avoid. You may want to get down on dog level and look for any sharp corners or other hazards for your dog. It is also a good idea to use safety gates around staircases and swimming pools so that blindness does not result in a traumatic accident.
2. Develop special commands
Sometimes you can teach your dog commands to help him or her know when to step up or jump up. For example, Clark’s foster mom taught him to “load up.” Whenever he heard that command he would trustingly take a flying leap up into the back of her car. She also taught him the word “step” so that he could navigate stairs a bit easier. Knowing a “stop” or “wait” command is also helpful for stopping your dog before he or she enters a dangerous situation.
3. Make (helpful) noise
Blind dogs also benefit from auditory signals. Clark would follow the sound of the other dogs’ tags jingling on a walk or listen for his foster mom clapping. His foster mom and forever family would talk to him often so he could follow their voices. This also helped him feel more confident in new situations and less likely to be startled. Additionally, it is important to remember that when you are calling a blind dog to you, you need to continue to call the whole time so that your dog can use your voice to locate you.
4. Use texture as a tactile marker
Blind dogs can also learn that changing textures under their feet indicate something to watch out for. Clark had a rug in front of the staircase so that he could tell he was on the laminate then the rug then the stairs. That helped him know where the stairs were. You can also put wood chips around the edge of your fence, trees, or bushes to act as an early warning system so your dog doesn’t run into them. Some dog parents will also put a rug at the door (inside and out) to help the dog know where it is.
5. Apply ToeGrips
Additionally, blind dogs can benefit from Dr. Buzby’s ToeGrips® dog nail grips. While slippery floors can be difficult for any dog, they are especially intimidating for blind dogs. This is probably because slipping creates a falling sensation that tends to take away the dog’s confidence. However, with the traction provided by ToeGrips, blind dogs can have a better idea of where their feet are and navigate their environment with confidence. Numerous dog parents have shared how ToeGrips for blind dogs have made a huge difference for their visually impaired pups.
6. Seek out helpful websites or books
For more ideas on how to help your blind dog, check out these resources:
- My blog, 7 Tips For Living With A Blind Dog
- The book Clark’s foster mom used to help him: Living with Blind Dogs: A Resource Book and Training Guide for the Owners of Blind and Low-Vision Dogs by Carol Levin
- The book Blind Devotion: Enhancing the Lives of Blind and Visually Impaired Dogs by Cathy Symons.
Clark “The Best Dog Ever”
As you may have guessed based on the things that Clark’s foster mom taught him about navigating the world while blind, he wasn’t a candidate for cataract surgery. The veterinary ophthalmologist suspected that his cataracts were secondary to a condition called Progressive Retinal Atrophy (PRA). This condition occurs more commonly in labs and renders the retina non-functional. As such, Clark had no chance of being able to regain his vision even if the cataracts were removed.
But that never kept him down. His mom described him as the “best dog ever” because he was so happy despite being blind and facing who knows what kinds of horrors in his former life. He greeted every person he met with a big doggie smile and a wagging tail and continued to happily launch himself into the back of the SUV to go on car rides.
Clark loved every dog, cat, and person he met, and they loved him too. He looked forward to his daily Kongs and of course being a Lab, he also loved the fact that his parents frequently showered him with treats. If you even touched the treat jar, he would come running from anywhere in the house with a wagging tail.
As his cataracts continued to progress, he did develop glaucoma. For several years it was well controlled with topical medications, but eventually the time came when his family thought that enucleation would be the best choice for him. Although his mom said she missed seeing his expressive brown eyes, she didn’t regret that decision because it made him much more comfortable.
When he passed away from cancer, his mom wrote, “I have never had a kinder, sweeter, more sensitive dog. He was such an inspiration to us. We learned so much about life from that old guy!”
Do you have a dog with cataracts?
Please share his or her story below.