Glaucoma in Dogs and Cats – An Emergency You Shouldn’t Ignore

By Brittany Schlesener, DACVO

Glaucoma is one of the most painful and vision-threatening eye diseases seen in dogs and cats. It happens when fluid builds up inside the eye, raising pressure to dangerous levels. Left untreated, glaucoma can cause irreversible blindness in just hours to days. Recognizing the signs early can make a life-changing difference for your pet.

What Does Glaucoma Look Like in Dogs and Cats?

The eye naturally produces fluid to keep tissues inside the eye nourished and healthy. In glaucoma, that fluid doesn’t drain properly due to hereditary or secondary disease processes (e.g., mass in the eye, uveitis, lens instability or luxation, etc.). Pressure inside the eye (intraocular pressure, or IOP) rises, causing pain and damage to the retina and optic nerve, which provide vital connections between the eye and brain.

Signs of Cat and Dog Glaucoma

• Redness of the white part of the eye
• Cloudy or bluish cornea
• Dilated pupil that doesn’t respond to light
• Sudden vision loss (bumping into walls, hesitancy with movement)
• The eye may appear enlarged or bulging in chronic cases (can become “chronic” as soon as 24-48 hours of uncontrolled eye pressure elevation)

Why Glaucoma Is a Pet Emergency

Glaucoma is not just blinding, but it’s extremely painful (i.e., migraine headache pain you probably cannot appreciate, even as the pet owner). Pets may rub or paw at their face, become lethargic, or even stop eating. Because vision loss from optic nerve damage is permanent, rapid diagnosis and treatment are critical.

Treatment Options for Glaucoma in Pets

• Medications: Eye drops and oral drugs can reduce pressure, but are often temporary measures.
• Surgery: Depending on whether vision is still present, surgery may aim to preserve sight (such as with glaucoma valve placement or a laser procedure) or relieve pain in a blind eye (enucleation or placement of a prosthesis).
• Monitoring: Regular checks with a veterinary ophthalmologist are essential, as glaucoma can affect both eyes over time.

Take-Home Message

If your pet’s eye suddenly looks red, cloudy, or painful, don’t wait—glaucoma is an emergency. Early treatment can relieve pain, save vision, and protect your pet’s quality of life.