Cataract prevention

I have a 12-month-old Jack Russell and I’ve read that they are prone to cataract problems when older. Are there any supplements or vitamins I can give my dog to help prevent this?

James Farrell advises…

Cataracts form in dogs’ eyes for a number of reasons. Due to a chemical change within the lens inside the eye, the clear cells become solid grey/white in colour, which then obscures a dog’s vision.

At first, it is a bit like looking through a frosted bathroom window and a dog will be able to see light, dark and shadows moving, but will lack focus. Advanced cataracts can block out all light, making a dog completely blind. Older dogs will often have ‘senile change’ occur to the eye and lens, making it grey/bluish in colour, which will reduce their vision, but these are not true cataracts – more a sign of an ageing pet and not really preventable.

One of the most common reasons for true cataracts is diabetes mellitus. The condition, like in humans, causes the dog to drink lots more water than usual and lose weight (although they are often overweight to start with). The cataracts form because the excess sugar in the blood circulation in diabetic dogs reacts in the lens of the eye, causing deposits to form, which are solid and white in colour. So, taking steps to try to prevent diabetes is worthwhile, but no vitamins will help prevent this occurring.

Although diabetes may occur in the best-looked after dogs, there are some steps owners can take to reduce the likelihood. We know that obese dogs are more prone to diabetes, so having regular vet check-ups or clinic weigh-ins are useful. Avoid excessive treats and certainly avoid human chocolate and sweets, as these will give a dog more sugar than needed.

Terriers are also particularly prone to lens luxation. This is when the lens becomes loose in the eye and slips forward to rest against the inside of the cornea. The lens may then turn cloudy and block the vision, but can also cause glaucoma where the pressure of the eye builds up. This is very painful and is an emergency condition, so get it seen by a vet straight away. Unfortunately, there is no particular way to prevent it, but through regular checks with your vet (for example, at the annual health and vaccination appointment) any eye changes may be picked up and if the lens has become loose, drops may be administered to close the pupil and so keep the lens back in the right part of the eye.

Also, by doing some weekly checks of ears, eyes, teeth and paws (which owners often do automatically without knowing it), you will be alerted to any changes, which you can then ask your vet about. Don’t stare for too long into your dog’s eyes, though, as some may see this as a bit threatening!