Glaucoma In Dogs: Causes, Symptoms And Treatment Advised by Vets

Glaucoma is an eye condition that occurs when fluid in the eye fails to drain properly. The build-up of this fluid, otherwise known as aqueous humour, causes increased pressure in the eye. This pressure can subsequently damage the optic nerve and retina, resulting in blindness.

For this article, we approached 3 veterinarians to gain greater insight into this topic.

Read on to learn more about the causes, symptoms and treatment for glaucoma in dogs as advised by pet experts.

Differences Between Cataracts, Glaucoma And Nuclear Sclerosis

Glaucoma, cataracts and nuclear sclerosis are conditions that affect the eyes. 

It’s often easy to confuse these conditions as they have a common symptom – cloudy eyes. Despite being different in nature, cataracts could also cause or worsen glaucoma

Hence, it’s critical to understand the differences between these three conditions and their implications.

Primary glaucoma is an abnormality of the drainage angle inherited in certain breeds of dogs. Due to this abnormality, drainage capacity is reduced and pressure builds up in the eye.

According to Dr. Joanna Woodnutt (MRCVS), breeds that more prone to this type of glaucoma include

  • Jack Russell Terrier
  • Great Dane
  • Beagle
  • Basset Hound
  • Cocker Spaniel
  • Dachshund
  • Poodle
  • Maltese

Secondary Glaucoma

When the drainage is physically obstructed, it’s classified as secondary glaucoma. 

Dr. Nick Garside (MRCVS) shared that this type of glaucoma is more common than primary glaucoma in dogs. It can be caused by an array of conditions such as

  • Retinal detachment
  • Lens luxation
  • Tumours that block the drainage
  • Blunt-force trauma to the eye, resulting in bleeding
  • Uveitis or inflammation in the eye, possibly due to cataracts

The symptoms of glaucoma include

  • Cloudy eyes and redness
  • Swelling of the eyes
  • Elevated third eyelid
  • Pain in the eyes (e.g. rubbing the eyes with his paws)
  • Loss of vision (e.g. bumping into objects)
  • Lethargy and loss of appetite

When To Consult A Vet

When you notice any of the above symptoms in your dog, it is crucial to visit a vet immediately. A vet will be able to make an accurate diagnosis of your dog’s condition.

Timely treatment is key to saving your dog’s sight if he’s indeed suffering from glaucoma.

Vets will first conduct clinical observations. They will then test the intraocular pressure of your dog’s eye using a tonometer. An intraocular pressure above 25mmHg may signal that your dog is suffering from glaucoma.

Certain vets may also conduct a gonioscopy or ultrasound scan to aid with the diagnosis. A gonioscopy uses a contact lens prism to view the drainage angle of the eye.

As glaucoma is not contagious, pet owners don’t need to be cautious of being around their dogs if they’re diagnosed with the condition.

Treatment For Glaucoma

Depending on the severity and cause of your dog’s glaucoma, different treatment options may be advised by your vet.


Medication may be applied or injected into your dog’s eye to drain and/or reduce the fluid produced. This subsequently helps to reduce intraocular pressure.

Two medications that are commonly prescribed by vets include prostaglandin analogues and carbonic anhydrase inhibitors. Carbonic anhydrase inhibitors can be consumed (oral) or applied (topical), depending on your vet’s prescription.


Surgery may be used to decrease the pressure in the eye by draining the fluid or reducing the amount of fluid being produced.

However, according to Dr. Heather Venkat (DVM), the affected eye may have to be removed entirely in severe cases where other forms of treatment fail to work.

As dogs with glaucoma usually experience pain due to the buildup of pressure, removing the eye will help to relieve the pain and discomfort experienced by your dog.

Below are 2 common surgical recommendations for removing the eye.