Common Eye Problems of Dogs

Jul 13, 2020

Common Eye Problems of Dogs

Your dog’s sight is one of their most important senses, and an eye problem can interfere with their daily activities and comfort, as well as their vision. Upstate Vet’s ophthalmology department has experience in treating a variety of eye conditions in pets, from painful corneal scratches, to sight-impeding cataracts. Our team of dedicated, board-certified veterinary ophthalmologists will work with your family veterinarian to provide your pet with the best eye care available, for lifelong excellent vision and eye health. 


Although our ophthalmologists treat many different eye issues, these five conditions are most common in dogs.


Keratoconjunctivitis sicca in dogs

Keratoconjunctivitis sicca (KCS), or “dry eye,” is a common eye problem that interferes with eye surface lubrication. Tears are produced by lacrimal glands located around the eye, and in the third eyelid. Most dogs produce enough tears to keep their eye surface moist and healthy; however, dogs with KCS produce an inadequate tear volume, or tears of inadequate quality, that do not lubricate the eye surface sufficiently. KCS most often results from an immune-mediated deterioration of the tear glands, but can also result from other causes, including:

  • Drug reactions
  • Prolapsed third eyelid gland (i.e., “cherry eye”)
  • Third eyelid gland excision
  • Infectious, congenital, and endocrine diseases


Although any dog can develop KCS, the condition is genetically based in some breeds, including:

  • Cavalier King Charles spaniels
  • English bulldogs
  • Lhasa apsos
  • Pugs
  • Shih tzus 
  • West Highland white terriers


Dogs with KCS typically have red, painful eyes, with thick, mucousy discharge. Chronic corneal inflammation and trauma often cause secondary corneal ulcers and infections. Uncontrolled KCS can lead to corneal vascularization, pigmentation, and scarring, which can limit your dog’s vision. 


KCS is diagnosed by assessing your dog’s tear volume and quality. Treatment involves life-long eye medication to stimulate tear production, and reduce inflammation. 


Corneal ulcers in dogs

Common eye conditions in dogs

A corneal ulcer is an abrasion, scratch, or deeper wound on the eye surface that often results from ocular trauma, such as a scratch from another animal, or brush when a dog runs through the woods. Eye conditions that cause chronic corneal inflammation, such as KCS or abnormal eyelash growth, can also cause a corneal ulcer. These painful ulcers typically cause redness, squinting, tearing, and discharge, and possibly a cloudy-looking cornea. 


Corneal ulcers are diagnosed by applying fluorescein stain, which adheres only to non-intact corneal areas, to the eye surface. Most corneal ulcers are superficial, and resolve quickly with eye medications; however, deeper ulcers may require longer, more intensive treatment, and possibly surgery, to preserve vision, and save the eye.



Glaucoma is a painful, vision-threatening condition that causes increased intraocular pressure. The front of your dog’s eye is filled with a fluid called aqueous humor that is constantly produced and drained. Dogs with glaucoma develop an obstruction to aqueous humor drainage that causes the fluid to build up, increasing intraocular pressure, which can cause pain, redness, cloudiness, tearing, and eye enlargement. Pressure on the retina can rapidly lead to irreversible blindness, making glaucoma a medical emergency. 


Glaucoma is typically inherited, and is most often seen in high-risk breeds, including:

  • Basset hounds
  • Beagles
  • Chinese shar-peis
  • Chow chows
  • Cocker spaniels
  • Great Danes
  • Jack Russell terriers
  • Norwegian elkhounds
  • Samoyeds
  • Siberian huskies


Glaucoma can also develop secondary to ocular problems that interfere with aqueous humor drainage, including trauma, anterior lens luxation, ocular inflammation, advanced cataracts, and intraocular masses. Glaucoma can affect one or both eyes, depending on its cause.


Glaucoma is diagnosed by measuring your dog’s intraocular pressure with a specialized instrument called a tonometer. Glaucoma treatment involves life-long management, including eye medication administration and monitoring by a veterinary ophthalmologist. Despite treatment, some dogs lose sight in the affected eye(s), and may require surgical eye removal (i.e., enucleation) to control pain.


Cataracts in dogs

The eye’s lens is a transparent structure that helps focus light on the retina, which contains nerve fibers that transmit a visual image to the brain. A cataract is a lens opacity that interferes with vision. A cataract can affect part of a lens, or the entire structure. If a large portion of the lens is affected, the formed light beam cannot reach the retina, causing poor vision. A cataract appears as a white spot or haze in the center of your pet’s eye. 


Most cataracts are hereditary, and affect high-risk breeds, such as:

  • Bichon frises
  • Boston terriers
  • Cocker spaniels
  • Fox terriers
  • Havanese
  • Miniature schnauzers
  • Poodles
  • Silky terriers 


Cataracts can also develop secondary to injury, inflammation, or systemic diseases, such as diabetes mellitus. 


A cataract is diagnosed through a thorough eye exam by a veterinary ophthalmologist. Unfortunately, no medical treatment is available to slow or reverse cataract formation, and only surgical lens replacement will restore an affected pet’s vision.


Eyelid conformational abnormalities in dogs

As some dogs grow, their eyelids become disproportionately too short or long, which can cause secondary eye problems. Entropion is a condition where a dog’s eyelid rolls inward toward the eye surface. Hair contacts the corneal surface, and can cause chronic irritation and secondary corneal ulcers. Entropion has a genetic basis in several dog breeds, including Chinese shar-peis, chow chows, and Labrador retrievers. Entropion treatment involves surgery to correct the eyelid position, and alleviate the chronic irritation.


In a dog with ectropion, their eyelid margin is too long, and rolls away from the eye surface. Instead of adhering to the corneal surface, tears roll off, and the cornea becomes dry. Dogs typically have dull-looking corneas with mucousy discharge, and the chronically dry corneas are susceptible to irritation and ulcers. Breeds with loose facial skin, such as bloodhounds, have a higher incidence of ectropion, which sometimes requires surgery to shorten the eyelid margin. 


To learn more about the 'Top 5 Eye Conditions in Dogs & Cats', download our brochure.


Your pet’s eyesight is irreplaceable, and we’ll do everything we can to protect their vision. If you believe your dog has one of these eye issues, or another ocular problem, see your family veterinarian, or contact our ophthalmology department.

Veterinary Professionals