Glaucoma is a painful eye disease in which the pressure inside the eyeball, called intraocular pressure, rises to dangerous levels. The eye constantly produces fluid that drains out through a meshwork at the front of the eye; when drainage slows or blocks, fluid builds up and the pressure crushes the retina and optic nerve. Primary glaucoma is inherited and common in breeds such as Cocker Spaniels, Basset Hounds, Chow Chows, Shar-Peis, and Siberian Huskies. Secondary glaucoma develops when another eye problem, such as uveitis, a displaced lens, a tumor, bleeding, or trauma, blocks the drainage. In both forms, permanent blindness can develop within hours to days if pressure is not reduced quickly.
Signs and Symptoms
Acute glaucoma is dramatic and easy to miss only if you do not know the signs. Look for a red, bloodshot eye, a cloudy or bluish haze over the cornea, and a pupil that is wide and slow to react to light. The dog may squint, paw at the eye, produce watery discharge, and shy away when you touch the head. Many dogs simply become quiet, withdrawn, and off their food because the deep pressure pain resembles a constant headache. In chronic cases the eyeball itself enlarges or bulges, and vision loss shows up as bumping into furniture or missing stairs.
When to See a Vet
A suddenly red, cloudy, or painful eye is an emergency, not a wait-and-see problem. Contact your veterinarian or an emergency clinic immediately, ideally within hours of noticing the change, because every hour of high pressure costs retinal function. Vets measure the pressure with a quick, painless test called tonometry; normal canine pressure is roughly 10 to 25 mmHg, and pressures climbing toward 40 to 50 mmHg demand emergency treatment. If your breed is predisposed, ask about baseline pressure screening in early adulthood so future changes are easier to catch.
Common Vet-Directed Treatments
The first goal is to bring the pressure down fast. Emergency treatment can include topical drops that reduce fluid production or improve drainage, oral or intravenous medications given in the hospital, and strong pain relief. Once the crisis passes, most dogs need long-term daily drops, and a veterinary ophthalmologist may recommend surgery such as laser therapy to reduce fluid production or drainage implants to improve outflow. When an eye is already blind and painful, surgical removal of the eye is the kindest option, because it ends the pain permanently. The vet will also watch the second eye closely, since primary glaucoma often develops there later, sometimes with preventive drops to delay it.
Home Care for a Dog with Glaucoma
- Give every drop exactly on schedule, even when the eye looks better; skipped doses let pressure climb again.
- Never use human eye drops or leftover medication, as some drugs that are safe for people are harmful to dogs.
- Use an Elizabethan collar if your dog rubs the eye, and keep fur around the eye trimmed.
- Attend every follow-up pressure check, and watch the other eye for the same early signs.
- If vision fades, keep furniture in familiar places and use textural cues so your dog can navigate confidently.
Prevention
Primary glaucoma cannot be prevented outright, but early detection preserves the most vision. Schedule regular eye examinations, and for high-risk breeds consider routine pressure measurements before symptoms appear. Treat eye inflammation, injuries, and cataracts promptly, because these are common triggers of secondary glaucoma. Do not dismiss a bluish haze as simple aging: normal age-related hardening of the lens looks different from the painful, red, pressured eye of glaucoma, and only a veterinary examination can tell them apart. When in doubt, have the eye examined the same day.
Disclaimer: This article is for educational content only and is not a substitute for professional veterinary advice. If your pet is unwell, please contact a licensed veterinarian promptly.