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.

We’d like to thank the following veterinarians for their insightful sharings regarding this topic:

  • Dr. Joanna Woodnutt (MRCVS) from The Veterinary Content Company,
  • Dr. Nick Garside (MRCVS) from VioVet.
  • Dr. Heather Venkat (DVM) from VIP Puppies.

  • *Disclaimer: The information and suggestions in this article are not meant to replace the advice of vets. Please consult a vet on your dog’s condition for accurate diagnosis and treatment.

    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.

    Infographic on the differences between cataracts, glaucoma and nuclear sclerosis

    Causes Of Glaucoma

    There are two types of glaucoma – primary and secondary glaucoma.

    Primary Glaucoma

    Basset hound in a field of grass looking straight ahead

    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 (Standard/Miniature/Toy)
    • 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

    Symptoms Of Glaucoma

    Brown dog with black patches of fur sleeping in a basket

    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.

    Diagnosis Of Glaucoma

    Vet with tools like a tonometer on a metal table

    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.


    White dog receiving eye drop treatment

    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.


    The eyelid is sewed together after the eye is removed.

      Intraocular prosthesis

    A prosthetic ball is placed into the eye after the inner parts including the lens, retina and iris are removed. This helps to maintain the shape of the eye.

    How To Care For Dogs With Glaucoma

    In some cases, long-term care is required for dogs with glaucoma. Making regular visits to the vet is important to ensure that your dog is responding to the treatment.

    However, in severe cases where dogs have lost their sight, it’s essential that the house is made as safe as possible for them. This could mean 

    • Sealing off dangerous places such as pools
    • Creating ramps to help your dog move up and down stairs easily and safely

    Prevention Of Glaucoma

    Dog with carrot in mouth lying in a field of grass

    There’s no concrete evidence that glaucoma in dogs can be prevented. However, according to Dr. Woodnut, sufficient levels of Vitamins A, C and E and beta-carotene may help to reduce the risk of inflammation in the eyes and carrots are a good source of all these nutrients.

    Despite this, inflammation is merely a single cause of glaucoma among many others.

    Early detection is, therefore, key to preserving your dog’s sight for as long as possible. Being attentive to changes in your dog’s behaviour and/or eyes can help in ensuring that they receive treatment as soon as possible.

    Treating Glaucoma In Dogs

    It’s often frightening and painful for a dog experiencing glaucoma. Thus, giving them access to treatment to reduce their pain or keep their sight as long as possible is crucial.

    In cases where surgery is necessary, pet insurance can help to cover the cost of surgical treatment, making it more affordable for pet owners.


    • Emilia Wong


      Bubble tea and sleeping are two of Emilia's favourite things. She also enjoys cooking and loves to experiment with new recipes for different cuisines.


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