Humans and dogs share very similar eye structures, meaning that our pooches can develop many of the same eye conditions that us humans get.
Cataracts is a common eye condition in both humans and dogs, and it is characterised by an unusual cloudiness covering the lens of either one or both eyes.
Usually developing gradually, cataracts are one of the main triggers that lead to deteriorating vision in dogs and can often result in total blindness.
To understand what cataracts are, it’s im-paw-tent to know the structure of the eye and how it works. In a healthy eye, light will pass through the lens and reach the retina at the back of the eye. The lens is a transparent disc and works by focusing the light onto the retina and consequently producing an image.
Cataracts is when the lens becomes hazy and cloudy, inhibiting light from entering the eye and in turn causing your pooch’s vision to be obstructed. To begin with, the cataract might only be a tiny speck or a slight cloudiness that’s barely even noticeable, not impacting your dog’s vision much at all.
However, it’s often a progressive eye condition and will likely get more severe. Eventually, it could look like a completely opaque white/grey disc behind the iris (the coloured section of the eye) which will seriously hinder your dog’s sight.
Cataracts can often be mistaken for another common eye condition in dogs called nuclear sclerosis, as this also manifests itself through a peculiar cloudiness in the eye.
Nuclear sclerosis is simply just the lens changing as your dog grows older, but if you notice any kind of haziness you should contact your vet quickly to find out what it is.
Genetics play a huge role in the development of cataracts. Parent pooches should be screened prior to breeding to ensure the condition isn’t passed down to their litter. Certain breeds are, for some reason, more predisposed to cataracts, for instance, Miniature Schnauzers, Poodles, Cocker Spaniels and Golden Retrievers, to name a few.
Also, cataracts are extremely common in diabetic dogs as the high levels of blood sugar can build up in the lens, resulting in the cloudy appearance. Other conditions that trigger the onset of cataracts are glaucoma and uveitis.
Finally, cataracts can occur merely because of old age. This typically develops very gradually and an owner might not notice it for quite a while.
Realistically there is only one main symptom of cataracts and that’s the clouded eyes, in severe cases it might completely block out your dog’s eye colour.
In early cases of the condition, the grey/white tinge might be barely noticeable, only becoming visible when the light catches it or when you’re taking a cute photo of your pooch.
Healthy eyes should be bright, with the whites and iris clearly visible. Also, they should be free of redness, dirt or discharge which could be indicators of other common eye conditions such as conjunctivitis.
Vision loss is a side effect of cataracts, but this can be quite tricky to notice as it often slowly worsens over time rather than happening overnight.
Dogs actually cope relatively well with their sight deteriorating as their keen sense of smell helps them to navigate. Watch out for your pup appearing disorientated or bumping into furniture.
Cataracts alone doesn’t cause any pain for your pooch, but if it’s developed due to another condition, such as glaucoma, this can be painful.
A vet will begin with a thorough examination of your pup’s eyes to diagnose them with cataracts. They can even detect it if it’s only just started to form and hasn’t really caused your dog any troubles with their vision yet.
For some dogs, surgery is an option to restore their vision. The surgery is executed under anaesthetic and works by replacing the defected lens with a replacement lens made out of plastic.
After surgery your pup will be required to wear a protective cone to prevent them from rubbing their eyes. Wearing a cone is most dogs’ worst nightmare, so it might be a struggle to convince your pooch to keep it on…
Luckily, surgery typically proves to be an effective treatment, enabling many pooches to have their vision pretty much fully restored. However, surgery isn’t a viable option for all dogs, so consult your vet for advice.
Cataracts can also appear as a result of a different condition, such as diabetes or glaucoma. If so, these conditions will need to be treated first to inhibit the development of cataracts. Hopefully, this should slow down the progression, although it won’t eradicate it completely.
Many dogs cope really well with the condition, not letting it impact their life too much.
With all vision problems, it’s best to try and keep everything in your house in the same place. For example, try not to have a complete rearrange of the furniture, and don’t relocate their bed, food bowl and water bowl.
Dogs are pretty clever and due to their intense sense of smell, most can find their way through the house relatively bump free.
Unfortunately, there’s no way of preventing your dog from developing cataracts. However, taking precautions very early on can help.
If you’re wanting to add a furry friend to your family, especially one of the breeds listed earlier that are prone to developing cataracts, ensure you are going to a reputable breeder. Both puppy parents should have been screened under the Eye Scheme, which identifies any inherited and non-inherited eye conditions in dogs.
Even though cataracts can cause severe sight damage, our dogs are tough and resilient little animals, so most will respond and adapt well to the condition.
As a pooch paw-rent, the main thing you can do is be patient and understanding with your dog, especially if they keep accidetally bumping into things in the house!
Written by: Dr Andrew Miller MRCVS
Andy graduated from Bristol University in 2010 and sees nutrition as a foundation for our pet's wellbeing and takes a common-sense approach. We are what we eat, and it shouldn't be any different for our pets.