Glaucoma in Dogs
Glaucoma is a serious and painful condition in dogs that results from increased pressure inside the eye (intraocular pressure or IOP). If left untreated, glaucoma can cause irreversible damage to the optic nerve, leading to partial or complete blindness. Early recognition and treatment are critical to preserve vision and relieve pain.
What Is Glaucoma?
The eye constantly produces a fluid called aqueous humor, which normally drains through small channels. When these drainage pathways become blocked or impaired, fluid builds up inside the eye, increasing pressure. This pressure damages the optic nerve and other internal eye structures, ultimately affecting vision.
Types of Glaucoma
Primary Glaucoma: This form is inherited and often occurs in both eyes, although not always at the same time. Certain breeds are genetically predisposed, including Cocker Spaniels, Basset Hounds, Samoyeds, Beagles, Poodles, Chow Chows, and Siberian Huskies.
Secondary Glaucoma: This occurs as a result of another eye problem, such as inflammation (uveitis), trauma, lens luxation, or tumors that obstruct fluid drainage. Secondary glaucoma can affect any breed and usually involves just one eye.
Signs of Glaucoma
Redness of the eye
Squinting or excessive blinking
Cloudy or bluish appearance of the cornea
Dilated pupil that may not respond to light
Vision loss
Eye may appear larger or bulging (buphthalmos) in chronic cases
Pain, often shown as lethargy, decreased appetite, or withdrawal
Because dogs cannot communicate vision changes, behavioral clues are important. Owners may notice their dog bumping into objects or hesitating in unfamiliar areas.
Diagnosis
A veterinarian can diagnose glaucoma by measuring intraocular pressure using a device called a tonometer. Additional tests such as gonioscopy or ultrasound may be used to assess the drainage angle or internal structures of the eye, but will require a veterinary ophthalmologist. Because glaucoma can progress quickly, same-day evaluation is essential if symptoms are noted.
Treatment Options
Glaucoma is a medical emergency. Treatment focuses on lowering eye pressure and managing pain.
Medications: Eye drops and oral medications may be used to reduce fluid production or increase fluid drainage. These include drugs such as dorzolamide, timolol, and carbonic anhydrase inhibitors. At times, these medications are applied every few minutes at first, until the pressures begin to respond.
Surgery: In cases that do not respond to medication, surgery may be needed. Options include laser procedures to destroy part of the fluid-producing tissue or drainage implants to redirect fluid out of the eye.
Enucleation: In advanced or painful cases where vision cannot be restored, surgical removal of the eye (enucleation) may be recommended to relieve pain and prevent further complications.
Prognosis
Prognosis depends on how quickly the disease is diagnosed and treated. Unfortunately, even with aggressive therapy, vision loss is common. About 40 percent of dogs with glaucoma will go blind in the affected eye within the first year. For dogs with primary glaucoma, the other eye may also be at risk.
Managing a Dog with Glaucoma
Provide a calm, safe environment to reduce stress
Administer medications exactly as prescribed
Attend regular follow-up exams to monitor pressure and adjust treatment
Consider protective eyewear or modifications at home for visually impaired dogs
Conclusion
Glaucoma in dogs is an urgent, vision-threatening condition that requires immediate veterinary care. Recognizing the early signs and seeking prompt treatment can help manage pain, slow progression, and potentially preserve vision. If you suspect glaucoma, do not wait—contact your veterinarian or a veterinary ophthalmologist right away.
