Understanding Glaucoma in Dogs

Glaucoma is a painful eye condition caused by a buildup of fluid inside the eye that increases pressure and damages the optic nerve. It’s also the leading cause of blindness in dogs, and if you’re reading this, you’re probably worried about your dog right now. Whether you’ve noticed signs like a cloudy or bulging eye, or your vet has just mentioned glaucoma, that concern is completely valid.

Acting quickly matters. In acute cases, irreversible blindness can occur within 24–72 hours without treatment. This guide is here to help you understand what’s happening and what you can do.

What is glaucoma in dogs?

Glaucoma in dogs is a condition where fluid builds up inside the eye, causing increased intraocular pressure (IOP). Under normal conditions, this fluid, called aqueous humor, drains through a specific part of the eye. In glaucoma cases, that drainage gets blocked, leading to a dangerous pressure buildup that damages the optic nerve and retina. This damage results in pain, vision impairment, and, if untreated, blindness.

There are two main types of glaucoma in dogs: primary and secondary. Primary glaucoma is hereditary and affects specific breeds, while secondary glaucoma is caused by other eye conditions like uveitis (inflammation), lens luxation (displacement), or trauma.

Signs of glaucoma in dogs

Dogs are experts at hiding pain, so by the time symptoms of glaucoma appear, the condition may already be advanced. Keep an eye out for the following signs:

• Bulging or enlarged eye
• Redness in the white part of the eye
• Cloudy cornea (the clear outer part of the eye)
• Excessive tearing or discharge
• Squinting or keeping the eye closed
• Pawing at the eye or rubbing it against surfaces
• Dilated pupil that doesn’t react to light
• Sudden vision loss

If you notice one or more of these symptoms, especially in high-risk breeds like Basset Hounds, Cocker Spaniels, or Siberian Huskies, call your vet immediately. Early treatment can save vision and alleviate pain.

What causes glaucoma in dogs?

Glaucoma can develop for a variety of reasons. In primary glaucoma, the cause is usually a genetic defect in the eye’s drainage system. This type typically progresses slowly but often affects both eyes over time.

Secondary glaucoma, on the other hand, happens because of another eye problem. Common secondary causes include:

• Uveitis: Inflammation inside the eye that blocks drainage.
• Lens luxation: When the lens shifts out of position and obstructs fluid flow.
• Intraocular tumors: Growths that disrupt the normal eye structure.
• Trauma: Injuries that damage the eye’s drainage system.

Certain breeds are at significantly higher risk for primary glaucoma, including American Cocker Spaniels, Basset Hounds, Chow Chows, Shar-Peis, Siberian Huskies, and Norwegian Elkhounds, making regular eye monitoring especially important if you have one of these breeds.

How is glaucoma diagnosed?

Your vet will use a combination of tests to confirm glaucoma and determine the underlying cause. These may include:

• Tonometry: A quick, painless test that measures intraocular pressure using a handheld device called a tonometer. Normal pressure in dogs typically falls between 10–25 mmHg, though the exact range can vary slightly by instrument and technique. Glaucoma is generally confirmed above 30 mmHg, and in acute cases, pressure can exceed 40 mmHg or higher.
• Gonioscopy: An exam that looks at the eye’s drainage angle to identify structural abnormalities that may be causing the blockage.
• Ophthalmoscopy: A detailed look at the retina and optic nerve to assess damage.
• Imaging: Techniques like ultrasound or CT scans to detect underlying issues like tumors.

These tests help your vet decide the best course of action to manage your dog’s condition.

Treatment options for glaucoma in dogs

Glaucoma treatment focuses on reducing eye pressure, relieving pain, and saving vision if possible. Your vet may recommend:

Emergency treatment

In acute cases, vets use IV medications like mannitol or topical carbonic anhydrase inhibitors to quickly lower intraocular pressure and try to save vision. This is a critical step, as untreated glaucoma can result in blindness within 24–72 hours.

Long-term medication

Glaucoma often requires lifelong management with medications like prostaglandin analogs, beta-blockers, or carbonic anhydrase inhibitors. These help to either reduce the production of fluid inside the eye or improve its drainage.

Surgical options

If medications don’t control the pressure, surgery may be necessary. Options include:

• Cyclophotocoagulation: Laser surgery to destroy fluid-producing cells.
• Shunt implantation: A small device to drain excess fluid.
• Eye enucleation: Removal of the eye in cases of severe pain and vision loss. Dogs adapt remarkably well after this procedure, and removing the source of pain can significantly improve their quality of life.

Can pet insurance cover glaucoma?

Yes, glaucoma is covered under Lemonade Pet’s base accident and illness policy, as long as it isn’t pre-existing. That includes eligible costs like diagnostic testing, surgery, and the ongoing medications that are typically part of managing the condition long-term.

Glaucoma often requires consistent monitoring, regular appointments to check eye pressure and assess how your dog is responding to treatment. Lemonade’s Visit Fee add-on can help cover the exam fees tied to those check-ins, so the steady drumbeat of ongoing appointments doesn’t become a financial burden on top of everything else.

Before we go

Glaucoma in dogs is a time-sensitive and painful condition, but quick action can make all the difference. If you notice symptoms like redness, cloudiness, or a bulging eye, don’t wait to contact your vet. The goal of treatment is to reduce pain and protect your dog’s quality of life for as long as possible, and many dogs do well with the right care in place.

If you don’t have a pet insurance policy yet, it’s worth taking a few minutes to explore your options. Getting a quote is straightforward, and having coverage before anything develops puts you in a much stronger position when it matters most.

Frequently Asked Questions

A few quick words, because we <3 our lawyers: This post is general in nature, and any statement in it doesn’t alter the terms, conditions, exclusions, or limitations of the policies issued, which differ according to your state of residence. You’re encouraged to discuss your specific circumstances with your own professional advisors. The purpose of this post is merely to provide you with info and insights you can use to make such discussions more productive! Naturally, all comments by, or references to, third parties represent their own views, and Lemonade assumes no responsibility for them. Coverage may not be available in all states. Please note that statements about coverages, policy management, claims processes, Giveback, and customer support apply to policies underwritten by Lemonade Insurance Company or Metromile Insurance Company, a Lemonade company, sold by Lemonade Insurance Agency, LLC.  The statements do not apply to policies underwritten by other carriers.