Cataracts in dogs

Overview

• What is a cataract? A cataract is a cloudy patch in the lens of your dog's eye that causes blurry vision and potentially blindness.
• Causes: Cataracts can be caused by old age, hereditary factors, diabetes, eye injuries, and eye diseases such as glaucoma and uveitis.
• Symptoms: Signs of cataracts in dogs include cloudiness in the eyes, reduced vision, and sometimes pain.
• Diagnosis and Treatment: Vets diagnose cataracts using an ophthalmoscope (an instrument that examines the inside of an eye) and where possible may recommend surgery (phacoemulsification) to remove them. However, many dogs cope very well with cataracts, especially if they develop slowly.
• When to contact a vet: Always contact your vet if you notice any changes in your dog's eyes.

What is a cataract?

Inside each of your dog's eyes is a transparent, glass-like disc called a lens. The lens focuses images onto the retina (the back of the eye), helping your dog see clearly. A cataract is a cloudy patch that develops inside this lens. Cataracts block images from entering the eye, causing blurry vision and, if severe, can lead to blindness.

Cataracts in Dogs: A Visual Guide

What causes cataracts?

Cataracts can be caused by:

• Old age – older dogs often develop cataracts due to changes in the fibre and protein inside their lens, which is part of the natural ageing process. Fortunately, old age cataracts tend to develop slowly, meaning most dogs adapt well to their gradual change in vision.
• Diabetes – it’s extremely common for diabetic dogs to develop cataracts because high blood sugar causes lenses to swell and turn cloudy. Diabetic cataracts often develop quickly and can cause a complete loss of vision, which can be distressing for the dog.
• Eye injury – eye injuries (even minor ones) can cause inflammation inside the eye and cause cataracts.
• Eye disease such as:
  • Glaucoma (high pressure inside the eye)
  • Lens luxation (when a lens moves out of its normal position)
  • Uveitis (inflammation inside the eye)
  • Progressive retinal atrophy
• Hereditary cataracts - certain breeds of dogs such as Golden Retrievers, Labradors, and Miniature Schnauzers are at high risk of developing cataracts. Some are born with them (which is known as congenital cataracts), but more commonly they develop later in life.

Other causes of cloudy eyes

• Nuclear sclerosis – A very common and harmless condition, found in older dogs. Nuclear sclerosis is a natural ageing process in which the lenses of the eye become denser throughout life, causing them to turn a blueish-grey colour. Nuclear sclerosis doesn’t affect vision unless it becomes very severe.

Symptoms

If your dog has a cataract, you might notice:

• Cloudiness in the affected eyes – they might look milky white, grey or blue.
• The affected eyes stop reflecting in night-time photographs.
• Reduced vision – they might start bumping into things, especially in low light conditions.
• Pain - cataracts aren’t painful, but some of the conditions associated with them (such as uveitis or glaucoma) are. So, if any of these other conditions are present, you may notice squinting, weepy eyes, red, bloodshot eyes, bulging eyes or your dog rubbing their face.

The signs of cataracts developing are not always as obvious as you might expect, especially if they develop slowly, over a long period. Most dogs are very good at adapting to loss of vision by using their hearing and sense of smell instead.

Diagnosis

Your vet will use a special instrument called an ‘ophthalmoscope’ to look inside your dog’s eyes. They might also use a ‘tonometer’ to measure the pressure of your dog’s eyes. If your vet is suspicious of any underlying problems such as diabetes, they may suggest blood and urine (wee) tests.

Treatment

Cataract surgery

• Cataracts can only be treated by surgically removing them. This is a delicate procedure that can only be performed by a specialist eye vet (ophthalmologist) and isn’t suitable for every dog due to the potential risks.
• Your dog has the best chance of a successful surgery if they are generally healthy, have no other serious eye problems, and can tolerate eye drops after surgery (to prevent infection and swelling).
• If you're considering cataract surgery for your dog, your vet will refer you to an eye specialist who will thoroughly examine your dog to determine if they're a good candidate.
• Having surgery sooner rather than later may mean a higher chance of it being successful. The surgery, called phacoemulsification, involves inserting a tiny probe into the eye. This probe emits high-frequency ultrasound waves to break the cloudy lens into small pieces. These pieces are then suctioned out, and an artificial lens is implanted as a replacement. The eye is then closed with stitches.
• After surgery, your dog will need regular eye drops, careful nursing care, and frequent check-ups with your vet.
• While cataract surgery is generally safe and successful, as with any surgery, there are potential complications which your vet will discuss with you before you decide if surgery is the right option for your dog. Possible complications include pain, vision loss, or even the need for eye removal in severe cases.

Leaving cataracts without surgery

Many dogs cope well with cataracts, especially if they’ve developed slowly and their vision loss is gradual. So, if surgery to remove the cataract(s) isn’t an option or the right choice for your dog, there are still many ways to help them.

Your vet may advise check-ups to monitor for any potential complications like uveitis or glaucoma (which can usually be managed with eye drops). One of the best things you can do to support your dog is to keep their home environment familiar and consistent. For more hints and tips on caring for a visually impaired dog, read our article blindness in dogs.

Reassurance for Dog Owners

It's understandable to worry about your dog's vision loss. However, many dogs with cataracts live happy and fulfilling lives. With a little extra love, patience, and some adjustments around the house, your dog can thrive even with reduced vision.

Preventing cataracts

• Always have eye injuries checked by your vet (even if they’re minor).
• If you are considering getting a breed of dog known for their risk of eye disease, make sure their parents have been screened under the ‘Eye Scheme’. The Eye Scheme is run by the British Veterinary Association, the Kennel Club and the International Sheep Dog Society and currently screens 65 dog breeds for 11 types of inherited eye disease (including cataracts).

When to contact your vet

Contact your vet if you notice any changes in your dog’s eyes, or if you think they are losing their vision.

You know your dog best, always contact your vet if you’re concerned.

Cost

Treatment for cataracts can become very expensive, so it’s important to speak openly with your vet about the cost of treatment, your finances, and what you think is right for your dog.

Consider insuring your dog as soon as you get them, before any signs of illness start to ensure you have financial support to care for them.

FAQs

Published: July 2024