By Dr. Becker
Recently I ran across a list titled "The 26 Biggest Health Conditions That Plague Dogs."1
The list was compiled by PetBreeds, and includes many disorders I've covered here at Mercola Healthy Pets, such as hip and elbow dysplasia, patellar luxation (floating kneecap), gastric dilatation volvulus (bloat), seizures, allergies, and musculoskeletal diseases.
What I find interesting about the list is the number of conditions (9 of 26!) that involve a dog's eyes. These include:
A condition in which the lower eyelid folds inward, resulting in pain, irritation and excessive tearing.
Cataracts give the eyes a cloudy appearance and can cause blurred vision.
✓ Progressive Retinal Atrophy (PRA)
An inherited condition that can cause impaired night vision, diminished peripheral vision, and/or complete blindness.
A condition in which extra eyelashes grow from the eyelid, which may or may not be problematic for the dog.
A condition in which the lower eyelid droops or rolls out from the surface of the eye, causing red, watery, and irritated eyes.
✓ Lens Luxation
An inherited condition in which the lens dislocates and can damage the optic nerve, causing blindness.
✓ Keratoconjunctivitis Sicca (KCS)
KCS (dry eye) describes faulty tear glands that cause dry, irritated eyes and can permanently impair vision and result in blindness.
A condition in which fluid accumulates inside the eyeball, which can eventually damage the optic nerve.
A condition in which eyelashes grow in the wrong direction, causing pain, irritation and potentially, injury to the eye.
In my experience, most people don't give much thought to the health of their dog's eyes, but as you can see from the list, there are a number of things that can go wrong with your pet's peepers.
Keep an Eye Out for These 9 Canine Eye Conditions
1. Entropion. A dog with entropion will typically squint and have an excessive amount of discharge from the affected eye. Sometimes there can be sensitivity to light and pawing at the eyes, especially when the dog is outside.
Other signs of entropion include inner eye inflammation (which is called keratitis), an eye tic, a sagging of the skin around the eye socket, or in worst-case scenarios, a rupture of the cornea.
Some cases of entropion are never more than a minor annoyance, while more severe cases can cause significant pain, eye ulceration, scarring, and ultimately, loss of vision.
2. Cataracts. Cataracts form a blue cloud of varying degrees inside the capsule that houses the lens of the eye. Cataracts can progress very slowly over many years or they can come on very quickly, leading to blindness within a few days or weeks.
Cataracts in dogs are often inherited. They can also be caused by diabetes, toxicity from drugs and pest preventives, another underlying eye disease, trauma to the eye, nutritional deficiencies in puppies, and as part of the aging process.
If your dog is diagnosed with cataracts, less troublesome ones will be rechecked periodically to see if they're progressing. Sometimes anti-inflammatory eye drops are prescribed.
But if your pet's vision is affected, her quality of life is compromised, or the cataracts are progressing rapidly, surgery is sometimes recommended to restore vision.
3. Progressive Retinal Atrophy (PRA). PRA is an inherited disease that causes dogs to lose their eyesight over a period of months to years. PRA is most often seen in Cocker Spaniels, Border Collies, Irish Setters, Norwegian Elkhounds, Schnauzers, and Poodles.
The retina, which is in the back of the eye, is composed of rods that perceive light and cones that perceive color.
Normally the rods and cones mature by the time an animal reaches about 12 weeks of age, but in some pets with PRA, they never completely mature and may begin to degenerate at an early age.
4. Distichiasis. Excessive eyelash hairs growing from the dog's eyelids rub against the cornea, irritating it. The affected eye becomes red, inflamed, and may develop a discharge.
Dogs with the condition typically squint or blink a lot and tend to rub their eyes against objects such as furniture or carpet. In severe cases, the cornea can ulcerate and appear bluish in color.
5. Ectropion. The most common sign of ectropion is a distinctly droopy lower eyelid. Affected dogs also tend to have watery eyes, swollen or red conjunctiva, tear staining, inflammation and/or eye infections. Signs of ectropion often seem to improve, then recur at a later date. In severe cases, symptoms typically do not wax and wane and will not improve without treatment.
6. Lens Luxation. In some dogs, the supportive ligaments of the lens weaken or tear, which causes the lens to dislocate from its normal position. It can fall backward into the eye (posterior luxation), which is typically painless.
Alternatively, the lens can fall forward into the eye (anterior luxation), where it blocks drainage of fluid and can result in glaucoma or increased intra-ocular pressure (IOP), which is extremely painful and can cause permanent blindness. Weakness of the lens ligaments is known to be hereditary in terriers, the Chinese Shar Pei, and the Border Collie.
7. Keratoconjunctivitis Sicca (KCS). Dry eye is a condition in which the tear mixture, which consists of oil, mucus and mostly water, is absent. Only oil and mucus are being secreted, which is why pets with KCS have thick, yellow discharge from their eyes. The eyes get red and the cornea, in time, turns brown. If the condition isn't treated, blindness can result.
8. Glaucoma. In dogs, glaucoma is either primary or secondary. Primary glaucoma is inherited and occurs in many breeds, including the Cocker Spaniel, Basset Hound, Chow, Jack Russell, Shih Tzu, and the Siberian Husky. Primary glaucoma typically starts in one eye and eventually involves both eyes. Secondary glaucoma occurs when other eye diseases are present that inhibit drainage of the aqueous humor inside the eye.
These diseases include inflammation of the eye (uveitis), advanced cataracts, cancer of the eye, lens displacement, and chronic retinal detachment. The increasing pressure inside the eye from glaucoma causes pain. The pressure can get much higher in dogs than it does in humans, so we can assume the condition is more painful for dogs than it is for you or me.
The pain of glaucoma is most likely felt as a severe headache. You may notice your pet doesn't want to play, is irritable, or perhaps his appetite is off. You might also notice he's rubbing or pawing at his eye or face. Sometimes dogs will rub their faces against furniture or another object in the home. Some will have fluttering of the eyelid, squinting, or will hold their eyes closed. Another sign is a dilated pupil in the affected eye.
Loss of vision is another symptom and often that is what brings pet owners to the vet. Unfortunately, permanent blindness can occur within a matter of hours, in cases of rapidly developing glaucoma where the pressure inside the eye becomes very high, very quickly.
9. Trichiasis. Trichiasis is common in brachycephalic breeds with flat noses and prominent eyes, such as the Pekingese, Pug, and Bulldog, as well as breeds with long hair around their eyes, such as the Cocker Spaniel. Trichiasis can cause squinting or blinking of the eyes, excessive tearing, eyelid twitching, swelling, blood vessel invasion of the cornea, and pigmentation of the iris (the colored portion of the eye).
Any noticeable changes in your dog's eyes or her ability to see should prompt a phone call to your veterinarian. I recommend you have your canine companion's eyes examined as soon as possible to determine exactly what's going on, and whether treatment is needed.