Glaucoma in Dogs

Causes, Treatment, and Prevention

Dog getting an eye exam.

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Glaucoma is an eye disease that occurs in dogs as well as humans. It causes an increase in ocular pressure, which can be very painful and cause permanent damage if left untreated. Knowing the signs of glaucoma in a dog can help you recognize the problem and seek early treatment for your pup's eyes.

What Is Glaucoma?

Glaucoma is a painful disease that occurs when the pressure inside a dog's eye is too high. Normal intraocular pressure (IOP) is between 10 and 25 mm Hg, but dogs with glaucoma have eye pressure exceeding 25 mm Hg.

Symptoms of Glaucoma in Dogs

Dogs that have glaucoma experience constant discomfort and even pain due to the high pressure in their eyes. Because of this pain, a dog may exhibit symptoms that resemble those of other eye conditions and should be evaluated by a veterinarian.


  • Pawing at an eye
  • Rubbing an eye on the ground
  • Holding an eye shut
  • Bulging eye or eyes
  • Excessive blinking
  • Redness of the eye
  • Cloudiness of the eye
  • Bumping into things
  • Enlarged pupil

If glaucoma has been present for some time, a dog's eye may appear to be bulging or larger than normal. The enlargement may also cause issues with blood flow and cause excessive redness or inflammation of the sclera—the part of the eye that normally appears white. In addition to the eye itself being enlarged, the pupil may be dilated (enlarged) due to glaucoma.

Glaucoma is also often seen along with other problems with the eye. Cataracts can cause glaucoma, so if a dog's eyes appear cloudy, both cataracts and glaucoma may be present.

Advanced glaucoma can cause blindness, causing dogs to bump into objects that they can't see well.

Causes of Glaucoma

There are several ways glaucoma can occur in dogs, including:

  • Cataracts: The reason why dogs can develop glaucoma with cataracts is due to the slipping of the lens in the eye. This movement of the lens can cause fluid in the eye to be unable to drain and build up in the eye increasing eye pressure.
  • Eye Inflammation: Eye issues that cause inflammation in the eye such as uveitis and infections can cause fluid drainage issues and result in glaucoma.
  • Eye Tumors: Tumors inside the eye can cause an increase in eye pressure.
  • Eye Injury: An injury to the eye can cause the lens to move; it can also cause inflammation or debris to block the normal drainage in the eye.

Diagnosing Glaucoma in Dogs

After a full physical examination and discussion of the symptoms you are seeing in your dog, a veterinarian will utilize a special instrument called a tonometer to gently tap the surface of the eye to get a pressure reading on the instrument. If the tonometer reads over 25 mm Hg, then glaucoma may be diagnosed.


Eye medications are typically used to lower the pressure in the eye. If the pressure is not able to be controlled with medications, then surgery to remove the eye may be performed to relieve a dog of the chronic pain from the high ocular pressure.

Prognosis for Dogs with Glaucoma

If the pressure within an eye stays over 25 for an extended time period, it can cause permanent damage to the optic nerve at the back of the eye. If the optic nerve is damaged, then permanent blindness can occur.

How to Prevent Glaucoma in Dogs

Regular physical examinations will help prevent a dog from developing glaucoma because your veterinarian will often notice concerning changes that can lead to glaucoma.