Inside the eye is a lens that focuses light on the back of the eye or the retina. Vision occurs at the retina. The structure of the eye is similar to a camera, which has a lens to focus light on the film. If the lens becomes opaque this is called a cataract. There are other reasons the lens can look cloudy, and consulting your vet is advised if you notice changes to the eye(s).
What causes cataracts?
The most common cause of cataracts in dogs is inherited cataract formation. Other causes include injuries to the eye or diseases such as diabetes mellitus ("sugar diabetes"). Some cataracts appear to occur spontaneously and are age related.
Are some breeds more prone than others?
Many breeds of dogs are affected with hereditary cataracts. Some of the recognised breeds include the American Cocker, Labarador Retriever, French Poodle, Boston Terrier and the Welsh Springer Spaniel, to mention a few.
Will your dog go blind?
If cataracts occupy less than 30% of the lens or if only one lens is affected, they rarely cause diminished vision. When the opacity covers about 60% of the total lens area, visual impairment is usually apparent. If the opacity progresses to 100% of the lens, the dog is blind. However, whether the cataract remains static or progresses will depend on the type of cataract, the breed and other risk factors. There are other causes of blindness that can be associated with the retina, the back of the eye. A vet will be required to perform an ocular exam to establish if vision is impaired.
Can anything be done to prevent your dog from going blind?
Veterinary ophthalmologists can remove cataracts and restore failing vision caused by cataracts in your pet. Most pets have few complications and return to normal activity, running and playing within just a few days of the surgery.
Your dog has a cataract. How old will he/she be before they go blind?
Since the major cause of cataract is hereditary, cataract progression varies from breed to breed and individual to individual. Cataracts will develop relatively early in life in some breeds while in others the first signs are detected when the dog is older and progression is so slow that dogs still have reasonable sight well into old age.
What to do if you think your dog has a cataract
If you suspect your dog has cataracts, please contact our pet healthcare team to make an appointment with a veterinarian. Following a veterinary check-up, if required, we can arrange a referral appointment to an opthalmologist to further evaluate your pet's condition and determine appropriate treatment options.