Vision

The Importance of Eye Health for Dogs

Although a dog’s sense of smell is their most powerful sense, their eyesight is one of the key senses, alongside hearing, for acquiring information about their surroundings.

Like humans, dogs experience eye changes with ageing. Retinal degeneration and cloudy lens (nuclear sclerosis) are common forms of eye problems that result in a decline of visual function in our dogs.

What Causes Eye Problems and Loss of Vision in Dogs?

Macular degeneration, vision loss and blindness in dogs is often the result of normal aging, injury, or disease.

Macular degeneration, a degeneration of the central area of the retina, the macula, is the most common eye problem in dogs as they age. It more often causes milder vision impairment but can lead to complete vision loss.

The incidence of diabetes which has seen a significant, and rapid, rise in dogs is playing a large part in eyesight problems, with obesity and nutrition the principal contributing factors.

Cataracts, another cause of eyesight degeneration, occur when the lens in your dog’s eye turns cloudy and prevents light from reaching the retina – referred to as nuclear sclerosis.

Glaucoma, a painful condition, is caused by an increase in the fluid pressure inside the eye and resulting damage to the retina and optic nerves.

Progressive Retinal Atrophy (PRA) is an inherited condition in which the retina deteriorates causing blindness affecting both eyes

Sudden Acquired Retinal Degeneration Syndrome (SARDS) is very similar to Progressive Retinal Atrophy that is usually painless and the deterioration of the retina. However, it develops suddenly and ends in total blindness in a matter of days or weeks.

High blood pressure, Cushing’s disease, heart, liver, and kidney diseases can also be a cause of vision deterioration and loss of eyesight.

Finally, corneal ulcers generally occur as a result of an eye injury or a foreign object that becomes lodged in the eye causing the cornea to ulcerate.

What You Can Do to Identify a Problem with Your Dog’s Eye Health and Vision

In the same way your dog can communicate their needs to you using their eyes, so to their eyes can tell you a lot about not just their eyesight but about their general health and wellbeing.

There are a number of ways you can recognise healthy eyes and also assess whether your dog needs to get specialist help from either your vet or in some cases an eye specialist.

• In a well-lit situation look at your dog’s eyes. They should be clear and bright and the white area around the eye should be white. The pupils should be the same size; and healthy eyes will be free of tearing, and any discharge or crusting in the corners of their eyes. If you see cloudiness, off-colour, yellowing whites, uneven pupil sizes or a visible third eyelid, you should have your vet check your dog’s eyes.
• Gently roll your dog’s lower eyelid down until you can see the lining. It should be pink, not red or white.
• If your dog has runny eyes or discharge, they may have something gritty in their eye. Using cotton wool that you’ve dampened in warm water, gently wipe from the corner of their eye outward. Be careful not to touch their eyeball or scratch the cornea. If this doesn’t clear up their runny eyes or discharge problem, they may have an eye infection. Make sure to take them to the vet if the problem persists so they can identify the issue.
• If your dog has longish coat hair in and around their eyes can be the cause of irritation to their eyes. If you are confident, you can clip the hair from around their eyes. Alternatively see a professional groomer or your vet.
• Protect your dog’s eyes when applying any form of spray or shampoo or conditioner to avoid potential irritation caused by chemicals that don’t agree with your dog’s eyes.
• If your dog is pawing or rubbing their eyes frequently this will usually be an indication that they have an issue that they may need help with.
• Certain breeds are more prone to eye issues – research whether your dog’s breed is more likely to suffer from eye issues through their life.

If you are in any doubt about the health of your dog’s eyesight or they seem to have a persistent problem, getting them to your vet for a thorough examination is your best course of action. Problems with eyes and vision rarely correct themselves.  On the contrary eye problems often worsen and without diagnosis and the appropriate treatment can deteriorate. Your veterinarian will not only check your dog’s eyesight but will assess your dog’s general health to identify what may be contributing to the problem. Early intervention, as with any medical issue, means any remedy or surgical treatments are more likely to be successful in rectifying the issue.

An entropion (a turned in eyelid where the eyelashes are continually scratching your dog’s eye) can be repaired relatively easily and with little impact on your dog’s day to day health.

Cataracts can cause the lenses of your dog’s eyes to become cloudy as they age, and like us, surgery to correct the issue is recommended for dogs. Cataract surgery enjoys a very good success rate in dogs with approximately 90% of dogs recovering their vision.

Other issues with your dog’s eyes, such as a bacterial infection, may simply require condition specific medication to clear up the problem.

In the case of corneal ulcers an eye specialist may discover a foreign body that is responsible for the ulcer and surgery may be needed to remove it.

With so many probable causes of eye and vision issues, your vet is your first choice for diagnosis and recommendation to solve any problems with your dog’s vision.

Should your vet consider it necessary to perform further diagnostic investigation of your dog’s eye issues, an ophthalmologist may be consulted. They will examine your dog’s eyes and may perform certain tests to identify the cause of the problem. These could include a Schirmer Tear Test which measures your dog’s tear production against the expected norm, a fluorescein stain evaluation to check for ulcers and a tonometry test to detect the presence of glaucoma in your dog’s eye.

What Can I Do to Support an Improvement in My Dog’s Eye Health and Vision

The 4 most common eye issues your dog is likely to suffer from are cataracts, glaucoma, macular degeneration and diabetic retinopathy.

As with any health issue, prevention is usually better than cure.

Nutrition is often your dog’s best defence against deteriorating vision as it is for many of the health issues they may face.

As with any disease state, inflammation and oxidation play a significant role in many dog eyesight issues.

In order to combat oxidation a diet that is rich in antioxidants is recommended.

Antioxidants scavenge free radicals, which cause oxidative damage throughout your dog’s body, including their eyes. Low levels of antioxidants in your dog’s diet correlate with an increased risk of cataracts, macular degeneration and possibly glaucoma; higher dietary intakes seem to protect against such age-associated eye diseases.

Lutein and zeaxanthin are phytonutrients, carotenoids in particular, that form the pigment for the macula, an area at the back of the eye that is key to visual acuity. These two carotenoids are both antioxidant and anti-inflammatory, helping filter out damaging blue light and ultraviolet light. Higher dietary intakes of lutein and zeaxanthin correlate with a reduced risk of cataracts and macular degeneration and may also slow the progress of macular degeneration.

Lutein and zeaxanthin are the most potent antioxidants for the prevention or reduction in the risk of age-related macular degeneration (AMD) and other eye-related diseases. These xanthophylls aid in eye health and have been shown to reduce the risk of several eye-related complications [1,2,3,4]. Vitamins A, C, and E are the most effective vitamins for reducing the risk of macular degeneration [5]. However, only vitamin A plays an essential role in the human retinal pigment epithelial cells, whereas vitamin C and vitamin E are known to act as antioxidants.

Foods rich in lutein and zeaxanthin include leafy green vegetable like spinach and kale, parsley, peas, romaine lettuce, carrots, potatoes, broccoli, baobab, oranges and fava beans and egg yolk.

Anti-inflammatory foods are also known to play a role in reducing vision related issues.

Omega-3 fatty acids are anti-inflammatory, help maintain the fluidity of cell membranes and protect the retina from oxidative damage. Higher intakes of Omega-3 (EPA and DHA) reduce the risk of macular degeneration and may even slow its progression (6). Omega-3 fatty acids may also help reduce dry eye syndrome too (7).

Foods rich in Omega 3 (particularly EPA and DHA) include seaweed and oily fish including salmon, tuna, mackerel and sardines.

Bonza’s plant-based food for dogs is packed full of anti-inflammatory and antioxidative ingredients including rich sources of lutein and zeaxanthin, Vitamins A, C and E and Omega-3 (EPA and DHA) and includes PhytoPlus®, a proprietary blend of phytonutrients designed to support a reduction in oxidation and inflammation in your dog’s body.

Bonza – Nose-to-Tail Good Health