Cataracts are seen in both humans and dogs. They can occur in puppies or adults and vision loss is the biggest concern that surrounds them. Treatment options are limited but effective, and some form of disease management may also be available depending on the type of cataract present. Knowing the signs of cataracts, what causes them, and how they're treated or managed can help you give your dog the help they'll ever need.
What are cataracts?
The eye is made up of several parts and the thick clear part of the eye behind the cornea and the colored iris is called the lens. The lens is made up of protein and water and reflects light onto the retina so that a dog can see. If the lens becomes damaged or can no longer reflect light, vision loss occurs. Cataracts are changes in the lens of the eye that make it cloudy or milky. This cloudiness blocks light from adequately entering the eye and therefore has a negative effect on a dog's vision. Cataracts are determined by how much of the lens they block and there are four types.
Early cataracts - This smallest type of cataract covers less than 15% of the lens.
Immature Cataracts – These cataracts can cover 15-100% of the lens, but a tapetal reflection is still present to reflect some light onto the retina.
Mature cataracts – Also known as fully developed cataracts, mature cataracts cover 100% of the lens and there is no tapetal reflection.
Hypermature cataract – In addition to covering 100% of the lens and not allowing tapetal reflection, resorption of the lens is seen in hypermature cataracts. This appears as a sparkling area in the lens and lens wrinkles and uveitis may also be present.
Cataracts usually mature over time, but in some young dogs they may regress and disappear. Cataracts are not the same as lenticular or nuclear sclerosis. This eye problem can also occur in adult dogs and causes their eyes to become cloudy.
- Signs of cataracts in dogs
- Signs of cataracts in dogs
- Cloudiness or opacity in the eye
- Running into things
The only true sign that a dog has cataract formation is if you see a cloudiness in your dog's eye. A change in the normally clear lens in the center of the colored iris is usually described as milky or cloudy. This clouding may cover only part or all of the lens. When all the lens is covered by cataract, blindness, a dog can go blind and a dog can run into things he used to be able to see. Cataracts are not painful, but may be the result of an underlying problem.
Cataracts cause cloudiness in the lens of a dog's eye.
Causes of cataracts
Some dogs are born with cataracts, but many dogs develop them as adults. There are several reasons why cataracts can develop. Some of these causes are:
Genetics - The most common cause of cataracts in dogs is genetics. These cataracts are called hereditary cataracts, even though they may not appear until a dog reaches adulthood.
Diabetes Mellitus – Diabetes is the second most common reason a dog develops cataracts1. If there is too much sugar in the eye fluid, more water accumulates and cataracts develop.
Trauma – Severe damage to the lens of the eye can lead to cataract formation.
Retinal Disease – While uncommon, late-stage retinal degeneration in dogs can cause cataracts.
Uveitis - If a dog has inflammation in his eye it is called uveitis which can lead to cataracts.
Age – With age comes age-related changes that can contribute to cataract formation
Diagnosis of cataracts in dogs
If you suspect your dog has cataracts, a complete eye exam should be performed by a veterinarian. Sometimes a vet who specializes in ophthalmology is recommended to be seen by your regular vet because of the extra equipment they need to examine the eyes. Special lights and lenses can be used to make parts of your dog's eyes visible and rule out other eye changes and concerns such as corneal ulcers or lenticular sclerosis. The location and cause of the cataract and how much of the lens is affected by the cataract determine how much vision your dog may or may not have and whether surgery is recommended to remove it.
Treatment of cataracts in dogs
While cataracts are not painful or life-threatening, surgery is widely considered the only proven treatment option to restore your dog's vision and get rid of the cataract. Not all veterinarians will perform cataract surgery, and the cost may be prohibitive for some dog owners, but it is curative. Eye drops to prevent post-operative infection and inflammation are normally prescribed, but a dog will see again after the cataract is removed. Regular eye exams are also necessary after surgery to continually monitor the health of the dog's eye.
In some dogs with immature cataracts, eye drops can be used to dilate the eye to improve your dog's vision. Vitamins, antioxidants, and various supplements are available to support eye health, but will not make cataracts go away. Some may also have no scientific proof of efficacy. A product called Kinostat3 has shown some promising results in slowing the progression of cataracts. It is for diabetic dogs only and requires lifelong administration to help prevent the progression of cataracts, but does not resolve them.
How to Prevent Cataracts in Dogs?
It can be nearly impossible to prevent cataracts from forming in your dog's eyes. Avoiding eye trauma and things that can contribute to the development of diabetes can reduce the chance of cataracts, but genetics can't be stopped if your dog has inherited cataracts. Breeding should be avoided in dogs with cataracts to reduce the chance that their offspring will develop them later in life.
High-risk breeds for developing cataracts
Some dog breeds may be more prone to hereditary or hereditary cataracts than others. While some of these breeds are affected at birth or as puppies, many do not develop noticeable cataracts until adulthood. More than 150 breeds are at risk of developing hereditary cataracts4 and include:
- American cocker spaniel
- Afghan hound
- Australian Shepherd
- Bichon frise
- boston terrier
- Chesapeake Bay retriever
- Entelbucher Sennenhund
- golden retriever
- German shepherd
- Havanese
- labrador retriever
- Miniature Schnauzer
- Norwegian buhund
- Rottweiler
- Siberian husky
- Staffordshire Bull Terrier
- Standard poodle
- Beam S, Correa MT, Davidson MG. A retrospective cohort study of the development of cataracts in dogs with diabetes mellitus: 200 cases. Veterinarian Ophthalmol. 1999;2(3):169-172.
- Urfer SR, Greer K, Wolf NS. Age-related cataracts in dogs: a biomarker of longevity and its relationship to body size. Age (Dordr) . 2011;33(3):451-460. doi:10.1007/s11357-010-9158-4
- Kador PF1, Webb TR, Bras D, et al. Topical KINOSTAT™ improves the clinical development and progression of cataracts in dogs with diabetes mellitus. Veterinarian Ophthalmol. 2010 Nov;13(6):363-8.
- Davidson MG and Nelms SR. Diseases of the canine lens and cataract formation. In Gelatt KN (ed): Veterinary Ophthalmology 4th Pg 859-887. Blackwell Publishing, Ames IA.
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