What to Know
Written By: Bren Parker
Vet-reviewed by Kevin Smith, DVM, Richmond Road Vet Clinic
The canine eye is quite similar to the human eye in its basic overall design. That being the case, dogs share many of the same eye health issues that we are prone to encounter and one of these issues is cataracts. In fact, cataracts are the most common cause for vision problems in dogs. Since so many dogs will develop cataracts in their lifetime, it’s important for dog owners to be informed about them, understand how they can impact a dog’s vision, and what treatment options are available.
What are cataracts?
Cataracts appear as a cloudy film across the eye. This opacity occurs on the lens, which focuses light on the retina, when fibers breakdown and create protein clusters.
It’s important to note that a cloudy haze on the eye doe not automatically mean that a cataract has formed. Nuclear Sclerosis is an eye condition that occurs in senior dogs and produces a similar haze in the eye. Unlike cataracts, nuclear sclerosis, does not decrease a dog’s vision and will not lead to blindness. A veterinarian can easily determine if the cloudy film in your dog’s eye is a cataract or nuclear sclerosis.
Credit: Dogster.com
How do cataracts impact vision?
Just because your dog has a cataract it doesn’t mean that it will impact their vision. Many dogs have slow growing cataracts that never cause any loss of vision. How much your dog’s vision is impacted by the presence of a cataract is determined by how much of the lens is covered. An incipient cataract can affect 10-15% of the lens and not cause any loss of vision at all, depending on where on the lens it is. On the other hand, cataracts that encroach on over 60% of the lens will impair that eye’s vision. A mature cataract affects 100% of the lens and causes significant visual impairment or total blindness. Cataracts can lead to the development of inflammation of the affected eye, which can further lead to the other issues, like glaucoma.
What causes cataracts in dogs?
Cataracts are most often caused by genetics, diabetes mellitus, injury, and age.
What dogs are at risk?
Any dog can get cataracts regardless of breed or age. However, there are factors that increase the chances of them developing such as genetics. Breeds more likely to have cataracts include Labs, Cocker Spaniels, French Poodles, Boston Terriers just like in humans, cataracts are more likely to develop as a part of the aging process. Dog with diabetes mellitus have a great risk of having cataracts. In fact, most will develop cataracts within the first year after diagnosis. Also, some dogs are given milk replacements as puppies that are lacking certain nutrients that will lead to cataracts forming.
How are cataracts diagnosed?
Your veterinarian can exam your dog’s eyes to determine the presence of cataracts. While just an opthalmoscope will usually reveal the cataract, your vet may decide to dilate the pupil to get a better view of the entire lens.
Treatment/ Prognosis
The only treatment for a cataract is surgery which involves removal of the lens and replacing it with an artificial one. This is not always the first line of choice for every dog. If your dogs vision is not impaired, your vet may suggest a wait and see approach, monitoring their eyes regularly for any progression. This also means being more vigilant about your pet’s eye health- watching out for irritation/inflammation, preventing injury and using any eye drops that may be prescribed. As many dogs have cataracts that never present a vision problem, this may be all your dog will ever need. Keep in mind, that dog’s can have reduced vision and still function fine and go about their normal life.
Others may have progressive cataracts that significantly reduce their sight and the individual risks of each dog has to be assessed differently. While cataract surgery has an 80% – 90% success rate, other factors should be considered: your dog’s age, their overall health, and how your pet’s temperament would do with the post-op recovery time of rest, little activity, wearing a cone, etc. Recovery periods can be a few weeks or a couple of months depending on each case.
