It’s no secret.  Dogs LOVE to be off-leash, especially in natural areas where there are interesting smells, room to run, and lots of nooks and crannies to explore.  The wagging tail, wide open smiling mouth and occasional bursts of maniacal high speed running and whirling leave no doubt that this is true.  Unfortunately these natural environments can put your dog at risk for developing a traumatic corneal ulcer.

What is A Corneal Ulcer?

A corneal ulcer is a common eye condition in dogs in which there is a loss of a portion of the outer layer of the cornea.  The cornea is the transparent outer layer of the eye that protects the contents of the eye and refracts light [1].  There are nerves in the cornea and an ulcer is very painful causing the dog to squint and paw at the eye and it also becomes watery.

Dog Squinting

Dog squinting because of a corneal ulcer in left eye.

The defect in the dog’s cornea can sometimes be seen with the naked eye in the right kind of light.  To diagnose an ulcer, the vet will apply fluorescein stain to the eye.  This stain attaches to the exposed layer under the ulcer and appears green, neatly defining the problem[1].

How Does a Traumatic Corneal Ulcer Occur?

A corneal ulcer is often caused by trauma to the eye.  Depending on the environment, there are many potential sources of eye trauma.  Some dogs will push their heads into bushes or sage brush to try to root out rabbits to chase, potentially gouging an eye.  Even the act of sniffing among weeds and twigs could cause a scratch.  Cheat grass is an especially menacing invasive species of grass whose abundant seeds not only work their way into your shoes and socks, but can get caught in a dog’s eye.  Sometimes these seeds, or other types of debris, can get caught under a dog’s third eyelid and cause a corneal ulcer. 

Dogs Walking Along Trail

Dogs walking on a trail lined with cheat grass.


Treatment usually begins with the application of an antibiotic ointment three times a day for two weeks.  If this fails, it is possible the ulcer developed a lip around the edge which will impede healing.  If this is the case, Adequan eye drops are applied three times a day for two weeks.  Adequan is a brand of polysulfated glycosaminoglycan which is thought to inhibit the presence of plasmin in the ulcer.  Plasmin is an enzyme that breaks down fibrin, a protein that occurs when blood clots.  Inhibiting plasmin prevents the breakdown of fibrin, which is thought to strengthen the cornea and promote healing [2].  If the ulcer does not heal with these treatments, surgery may be necessary.


Antibiotic ointment and eyedrops used to treat corneal ulcer in dogs.


The time and expense involved in healing an eye ulcer, not to mention the dog’s suffering, are incentive to find ways to avoid having it happen in the first place.  One of the obvious solutions is to stay in developed areas such as along city sidewalks or in city parks if you are lucky enough to live in a town that allows dogs to be in parks.  The dog will still be happy to go for walks on a leash, but there is a noticeable difference in the happiness level between leashed walks and off-leash walks.

A compromise is to avoid natural areas when cheat grass, or whatever plagues your area, is at its worst.  For cheat grass this is after it turns yellow and the seeds start to attach to everything that comes near it.  You would still have to take your chances on the dog poking its head into bushes and other debris, however.

Another solution is to outfit your dog with eye protection.  Doggles is a brand of goggles for dogs that is pretty effective.  They either look kind of cool or totally ridiculous, depending on your point of view, but they do the job.  Once you get them positioned properly and your dog gets used to them, the dog can go about his business with very little risk of eye injury.  And remember, your dog doesn’t know that the goggles look ridiculous, or kind of cool.

Dog Wearing Goggles

Dog wearing Doggles brand goggles.

Doggles Originalz Large Frame Goggles for Dogs with Smoke Lens, Chrome
Amazon Price: $25.50 $10.01 Buy Now
(price as of Sep 11, 2014)

Corneal ulcers are a common painful eye problem among dogs.  They can become infected, leading to complications such as blindness.  Even if there are no complications they can sometimes take a long time to heal, causing your dog a lot of misery.  It is a good idea to try to reduce the chances of your dog getting an ulcer due to trauma by avoiding brushy areas and cheat grass or by using eye protection.