Health and Nutrition

Eye Problems


Like humans, dogs can get cataracts. If the dog is in good health, cataracts can be surgically removed usually with good results.



Corneal Dystrophy

Corneal Dystrophy is an inherited condition that affects one or more layers of the cornea resulting in corneal opacities. Both eyes are usually affected, although not necessarily symmetrically. The opaque areas generally contain fatty deposits and chronic or recurring shallow ulcers may result, depending on the corneal layers affected.

Several breeds can be affected by this disorder including: The Airedale, Afghan Hound, American Cocker Spaniel, Basenji, Beagle, Bearded Collie, Bichon Frisé, Boston Terrier, Boxer, Briard, Cavalier King Charles Spaniel, Chihuahua, Chow Chow, Dachshund, English Springer Spaniel, German Shepherd Dog, Golden Retriever, Irish Wolfhound, Labrador Retriever, Miniature Pinscher, Nova Scotia Duck Tolling Retriever, Pembroke Welsh Corgi, Rough Collie, Samoyed, Shetland Sheepdog, Siberian Husky, and Vizsla.



Corneal Ulcers

    • Corneal Ulcers in Dogs and Cats — In this video from, Dr. Douglas Esson discusses corneal ulcers in dogs and cats. Dr. Esson specializes in eye care for animals and is board certified in veterinary opthamology. Dr. Esson will address what they are, how they are diagnosed and what treatment options are available. This information is not meant to replace the advice of your regular veterinarian.



Eyelashes that are abnormally located in the eyelid margin which may cause irritation.



Conformational defect resulting in eversion of the eyelids, which may cause ocular irritation due to exposure.



Conformational defect where eyelid margin inverts, or rolls inward, toward the eye causing eyelashes and hair to rub against the cornea resulting in ocular irritation.


Exposure Keratopathy Syndrome

Due to increased evaporation of tears and corneal exposure, chronic irritation of the eye is seen with Keratopathy Syndrome. Affected dogs experience chronic discomfort and are prone to ulceration of the cornea. This is a result of a combination of anatomic features including exophthalmos (protrusion of the eyeball), lagophthalmos (inability to close the eyelids completely) and macroblepharon (an exceptionally large eyelid opening, often associated with lower lid entropion). The result is inadequate blinking, and therefore reduced protection for the eye. Affected dogs experience chronic discomfort and are prone to ulceration of the cornea.

This syndrome is associated with a combination of anatomic features that are influenced by several genes affecting skull and facial conformation of several breeds.

Signs of irritation include reddening of the eye, increased tears and discomfort. Affected dogs are prone to eye injuries from dust, twigs, etc. Corneal ulcers may develop due to the increased corneal exposure. Over time, pigmentation of the cornea may occur and may eventually interfere with the dog’s vision.



Glaucoma is a leading cause of blindness in dogs and is the result of increased fluid pressure within the eye. If the pressure can not be reduced, there will be permanent damage to the retina and optic nerve resulting in visual impairment. Complete blindness can occur within 24 hours or can occur slowly over weeks or months and is usually very painful.

Glaucoma is an emergency. Treatment must be started as soon as possible if your dog’s sight is to be saved. Irreversible damage to the retina and optic nerve occur within a few hours of significant elevation of the intraocular pressure.


Keratoconjunctivitis Sicca (KCS) (Dryeye)

Caused by abnormal tear production due to a deficiency in production of the watery secretions from the lacrimal glands. Normal tears are essential for the health of the cornea. Deficient tear production causes chronic irritation of the cornea and conjunctiva resulting in corneal ulcers and eventually corneal scarring and can also result in blindness.

There is a predisposition to the development of KCS in the Bloodhound, Boston Terrier, Bull Terrier, English Bulldog, English and American Cocker Spaniel, Kerry Blue Terrier, Lhasa Apso, Miniature Poodle, Miniature Schnauzer, Pekingese, Pug, Sealyham Terrier, Shih Tzu, Standard Schnauzer, West Highland White Terrier, Yorkshire Terrier. In addition, congenital KCS (where the dog is born with the condition) is rare but has been seen in toy breeds such as the Yorkshire Terrier, Pug, Pekingese, and Chihuahua. KCS can also occur in any breed as a result of viral infection, inflammation, drug-related toxicity, or immune-mediated disease.

KCS can develop very quickly or more slowly, in one or both eyes. Usually, it is diagnosed in one eye first and then develops in the other eye within several months. The extent of discomfort is dependent upon the severity of the tear deficiency and the length of time the condition has been present. A dog displays irritation and discomfort by rubbing their eyes, squinting and being sensitive to light. The eye may appear reddened and inflamed and there may also be a thick mucous type discharge in and around the eye.

If left untreated, over the long term, the normally transparent cornea becomes thickened and scarred. Blood vessels and pigmented cells move into the cornea and blindness may result.

Tear stimulants and artificial tear replacements are used to treat KCS. This is not a cure but away to manage a frustrating, painful, and potentially blinding condition.



Abnormally large eyelid opening; may lead to secondary conditions associated with corneal exposure.



Affected dogs have prominent third eyelids and small eyes which appear recessed in the eye socket. This is often associated with other eye abnormalities, including defects of the cornea, anterior chamber, lens and/or retina. Microphthalmia is also seen with coloboma – a cleft in a portion of the eye, particularly the iris. Microphthalmia with cataracts is seen in the Akita breed.

Puppies with microphthalmia with cataracts usually have some visual impairment. The cataracts are unpredictable and may be progressive resulting in a worsening of vision, or they may mature and be reabsorbed, resulting in improved vision.

The condition is apparent in puppies once they open their eyes. The affected eyes will appear smaller than normal and recessed, the third eyelid will be more prominent as well.


Persistent Pupillary Membranes (PPM)

Persistent blood vessel remnants in the anterior chamber of the eye which fail to regress normally in the neonatal period.


Progressive Retinal Atrophy (PRA) / Progressive Retinal Degeneration (PRD)

PRA is a family of diseases involving the gradual deterioration of the retina. In the early stages of the disease, an affected dog becomes nightblind and cannot see well in dim lighting. As the disease progresses, daytime vision also fails. Provided that the affected dog’s environment remains constant, an affected dog can adapt quite well to this handicap. As the affected dog’s vision fails, the pupils become increasingly dilated, causing a “shine” to his eyes. The lens of the eyes may also become cloudy, or opaque, resulting in a cataract. It should be noted that while some breeds are affected early in life, others can develop PRA much later.

For further information, see:


Prolapsed Gland of the Third Eyelid (Cherry Eye)

The third eyelid (also called the nictitating membrane (or membrana nictitans) and haw) is a triangular shaped structure in the inner corners of a dog’s eyes that sometimes partly covers the eye. It consists of a t-shaped cartilage and a tear gland. The third eyelid is important in protection of the surface of the eye, and in tear production.

A prolapse of the gland occurs when the base of the gland flips up and is seen above and behind the border of the third eyelid. The prolapsed gland becomes swollen and inflamed. The condition frequently occurs in both eyes and is most common in young large breed dogs.

The condition causes chronic irritation of the conjunctiva and cornea, and if untreated, can lead to Keratoconjunctivitis Sicca


Retinal Dysplasia

This is an abnormality in the development of the retina. There may be no visual defect in affected dogs, therefore, will only be found when the eye is examined. It is a condition that is thought to be inherited in a number of breeds. The condition may also be acquired as an injury or due to viral infections, toxins and nutritional disorders.


All breeding dogs should be examined annually by a certified veterinary ophthalmologist. Most responsible breeders will register with the Canine Eye Registration Foundation (CERF) and receive a CERF number for their dog. If you are adopting a puppy, ensure that the breeder provides you with copies of certifications for both the sire and dam. In addition, you should ask to see a copy of the paperwork that was forwarded to CERF because the form may report on other issues that may not deny the dog a CERF number but could be of interest to you.


Note: This section of the Canada’s Guide to Dogs website is intended as a source of information only. It is not intended as a substitute for professional care. Always consult with your Veterinarian about health related matters.

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