Does Glaucoma cause Blindness in Dogs


Dogs with Glaucoma need to be treated immediately.

Glaucoma, a word born from the Greek language meaning hard or inelastic, is a painful condition which requires immediate medical care.  Should you observe a cloudy appearance in your dog’s eye, frequent blinking, unusual redness, the eye seeming to recede further into the head, a dilated pupil, enlarged eye, and/or loss of vision indicated by your dog bumping into furniture or walls you should see your veterinarian as soon as possible.  Even just one of these signs could mean your dog has glaucoma, an ocular disease and one of the ailments of what causes blindness in dogs.  How quickly your dog is treated could mean the difference between sight and blindness.  That means taking your dog to the an animal ophthalmologist the day you notice the symptom(s), not waiting.   Irreversible damage to the eye can occur just hours after the symptoms first appear.

Two categories of glaucoma exist– primary and secondary.   Primary glaucoma is a genetic condition which causes a physical defect within the eye.  It is less common than secondary glaucoma, but strikes at a young age and though the initial onset will affect one eye, the second eye will most likely be affected within several years.  Primary glaucoma most commonly affects Beagles, Cocker Spaniels, Bassett Hounds, Miniature Poodles, Chihuahuas, Siberian Huskies, Chows and Dachsunds. 

More prevalent is secondary glaucoma which results from another condition such as trauma, inflammation, infection or lens luxation.

Treatment can delay the progression of glaucoma and, if caught soon enough, can perhaps save the eye. 

What is glaucoma?

Essentially, glaucoma is the result of fluid buildup in the eye.  This creates high pressure within the eye and can destroy or damage the retina and optic nerve within several hours.  Glaucoma is very painful and can cause lethargy, inappetence, cause your dog to rub his or her eye with their paw or rub their head against you or furniture while trying to alleviate the discomfort.  It can also cause your dog to become easily agitated.

To better understand the mechanism of glaucoma, a brief look at the eye’s anatomy is helpful.  The eye’s shape is maintained by internal fluid.  Aqueous humour is the watery fluid found in the front or anterior part of the eye.  Vitreous humour is a gel-like fluid located in the rear portion of the eye between the lens and the retina. 

The aqueous humour constantly circulates through the front of the eye, bathing and nourishing the cornea and the lens.  It is secreted by the ciliary body, which sits on either side of the lens, and is drained by a filtration system located at an angle off to the side of the iris.  It is imperative that the generation and draining of the aqueous fluid remain in balance.  Should this system become unbalanced- usually the fault of an impaired drainage system –  it will create pressure within the eye.  This is the condition of glaucoma.  Without treatment the pressure will become so elevated so quickly that the retina and optic nerve can be damaged, resulting in blindness. 


The veterinarian will need your dog’s history of any trauma and behavior indicative of pain or loss of vision.  A device called a tonometer will be used to determine the level of pressure within the eye.  You will likely be referred to a veterinary ophthalmologist for further evaluation.   


Treatment, usually an eye ointment which may need to be given three times a day, will be started to restore the normal pressure within the eye and to provide pain relief. This can help to delay the progression of glaucoma. 

If the glaucoma is caused by an infection or trauma, antibiotics or surgery may be considered.  Surgical techniques may also improve the drainage of the aqueous humour. 

Should the eye need to be removed, a procedure called enucleation, be assured that the loss of an eye is usually not difficult for a dog to adapt to.  Depth perception will be affected, so be aware as your dog navigates.  Assistance may be needed until your dog becomes acclimated.

Muffin’s Halo

In the event that your dog becomes blind, one way of providing immediate assistance is by using a Muffin’s Halo which will prevent trauma to your dog by protecting the head and face.  Muffin’s Halo is a three-piece device, consisting of a harness, a set of wings and a halo.  The halo serves as a bumper and will make your blind dog feel more secure as he or she learns to navigate.