How do I know if my dog has glaucoma?

Glaucoma is a severe eye condition in dogs that can be extremely painful and can threaten a dog’s eyesight. It’s important for dog owners to be able to recognize signs of glaucoma in their pets and to seek emergency veterinary care right away. Read on to learn:

• What glaucoma is
• Symptoms of glaucoma in dogs
• How canine glaucoma is diagnosed and treated
• How an online vet can help if your dog has glaucoma symptoms

Glaucoma occurs when fluid builds up within the eye, causing a dangerous increase in intraocular pressure. Symptoms include bulging eye(s), eye pain, visible red veins in the whites of the eye(s), and abnormal pupils. Glaucoma in dogs cannot be diagnosed by symptoms alone, and it’s important to get an accurate diagnosis from a vet as quickly as possible. All forms of glaucoma can rapidly lead to permanent vision loss.

Glaucoma is an eye condition in which a buildup of fluid within the eye of a dog causes a dangerous increase in intraocular pressure, or pressure within the eye. Aqueous humor is a fluid that circulates in and out of the eyeball to keep it inflated and provide nourishment to the eye. In dogs with glaucoma, aqueous humor does not drain properly, causing an increase in internal eye pressure. The increased pressure can rapidly cause irreversible eye damage and severe eye pain. Glaucoma can affect one or both eyes.

Glaucoma in dogs can be congenital, primary, or secondary.

Congenital glaucoma is present at birth and usually begins to cause symptoms when the dog is less than a year old.

Primary glaucoma, or chronic glaucoma, refers to a group of eye disorders in which the area where the aqueous humor drains is malformed, resulting in decreased fluid drainage. Primary glaucoma usually affects both eyes and is associated with increasing age. It’s not fully understood why primary glaucoma occurs in dogs, but genetics seem to play a role due to certain breeds being predisposed to the condition.

Secondary glaucoma occurs when aqueous fluid cannot drain properly as a result of an eye injury or other eye condition, such as:

• Uveitis
• Eye cancer or tumors
• Cataracts
• Complication of eye surgery
• Lens luxation

Secondary glaucoma is more common in dogs than primary glaucoma and congenital glaucoma.

Canine glaucoma can also be classified based on the state of the drainage angle where the aqueous humor drains from the eye:

• Open: The drainage angle is normal and the obstruction is somewhere else
• Narrow: The drainage angle is more narrow than normal, causing the drainage of fluid to slow
• Closed: The drainage angle is closed off, preventing any fluid from draining

Open-angle glaucoma usually develops gradually and is not painful right away, making it harder for dog owners to detect. Closed-angle glaucoma, or acute glaucoma, causes a sudden, painful increase in eye pressure and is considered a medical emergency. All types of glaucoma can lead to increased pressure on the optic nerve, which leads to vision loss in the affected eye and puts the eye itself at risk.

Dogs at risk for glaucoma

Some dog breeds have a genetic predisposition for primary glaucoma, including:

• Basset hounds
• Cocker spaniels
• Dalmatians
• Great Danes
• Boston terriers
• Shih tzus
• Siberian huskies

It’s best to talk to a veterinarian about your dog’s overall risk for glaucoma and how often they should receive eye exams and testing.

Symptoms of glaucoma usually start out mild and subtle. Early symptoms include:

• Pupils that are slow to dilate
• Pupils remaining slightly dilated when they shouldn’t be
• Mild enlargement of the eye

It’s common for early symptoms to go unnoticed by pet owners. As the condition progresses and the intraocular pressure increases, symptoms become more severe and additional symptoms develop, such as:

• Squinting or blinking excessively
• Avoiding bright light
• Abnormal avoidance of having eyes, face, or head touched
• Bulging of the eye
• Constricted, slow-moving, or dilated pupils
• Prominent blood vessels in the eye
• Unequal pupils
• Eye deformity
• Cloudy eyes

It’s possible for an eye to build up so much pressure that it ruptures. This results in the eyeball noticeably shrinking within the socket. “Signs of vision loss generally aren’t apparent unless a dog has lost vision in both eyes,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “As a result, signs of vision loss are uncommon early in the course of the disease or if only one eye has been affected.”

Other conditions that can look like glaucoma

The symptoms associated with glaucoma in dogs can also occur with other eye diseases, such as:

• Uveitis
• Lens luxation
• Cataracts
• Dry eye
• Corneal ulcers or scratches

Some of these other medical conditions are much more common than glaucoma in dogs, especially in nonpredisposed breeds. However, these other eye conditions can also lead to glaucoma, and it’s possible for a dog with ocular symptoms to have more than one eye condition at a time.

Is glaucoma an emergency?

Canine glaucoma is considered an emergency. Immediate veterinary care gives the best chance of saving your dog’s eye and vision. It’s best to seek emergency veterinary attention if your dog is showing signs of glaucoma, even if the signs seem minor. Glaucoma symptoms are often missed until the condition has worsened, so that many dogs don’t receive treatment in time to save the eye or prevent severe eye pain. By the time a dog is showing advanced signs of glaucoma, it’s too late for early intervention that might have saved the vision in the affected eye. Other eye conditions have similar symptoms, so it’s important to get an accurate diagnosis from a vet any time your dog is showing ocular symptoms.

When a dog presents with eye symptoms, a veterinarian will do a thorough physical examination and eye exam. Glaucoma is diagnosed with an intraocular pressure test, or tonometry, that measures the pressure within the eye. Patients with glaucoma will have higher than normal pressure in their eye(s).

Additional diagnostic testing is often necessary to determine the type of glaucoma and what’s causing it. These tests may include:

• A complete ocular exam
• Gonioscopy
• Ocular ultrasound
• Electroretinography

If your dog is an at-risk breed, your vet may recommend regular eye examinations with glaucoma testing. This can help catch glaucoma early before it becomes an emergency.

Glaucoma occurs when the pressure in a dog’s eye is dangerously elevated. To treat glaucoma, that pressure needs to be lowered. Depending on the patient, pressure may be lowered with:

• Eye drops that decrease intraocular pressure
• Medications that decrease fluid production in the eye
• Manual drainage of excess fluid from the eye in surgery

Surgical removal of the eye may be needed if the eye is severely damaged or has ruptured. Additional medical treatment may be warranted if there is another eye condition present, such as an eye infection, inflammation, tumor, or injury.

The prognosis for primary glaucoma is guarded, which means it’s hard to know how it will turn out, even with aggressive treatment. It’s a chronic condition and requires lifelong monitoring and eye medication. Treatment options and prognosis for secondary glaucoma vary based on the underlying condition that caused it.

Glaucoma is not life-threatening but may result in a dog losing one or both eyes. However, dogs that are otherwise healthy can still have a good quality of life without their vision. Even though acute glaucoma is initially a painful condition, the pain passes as the eye continues to deteriorate from chronically high pressure.

Can I treat my dog’s glaucoma at home?

Acute glaucoma is an emergency and requires hospitalization for specialized treatment. Once the patient is stable, ongoing management of the condition may be continued at home. Dogs with primary glaucoma require lifelong treatment. Always follow your veterinarian’s treatment recommendations, and make sure to reach out with any questions and let them know of any changes in your dog’s eye health. Do not attempt to treat your dog’s pain or eye symptoms without a vet.

It’s important to talk to a veterinarian any time your dog shows symptoms of an ocular disease, even if the symptoms seem minor. Acute glaucoma is an emergency that shares symptoms with other eye conditions, such as eye infections and injuries. Some eye conditions, including glaucoma, immediately threaten a dog’s eyesight. Seek emergency care if a dog develops bulging eyes; enlarged, red, ropy veins in the whites of the eye; or changes to their pupils, even if the changes seem mild. Early detection and prompt treatment by a vet may increase the likelihood of saving your dog’s eye.

An online vet can help triage a dog with eye symptoms and advise you if your dog is having a medical emergency. In addition, treatment for glaucoma often involves eye drops, which can sometimes be difficult to administer in a stress-free way. A veterinary professional can offer advice and guidance through an online virtual care appointment to make medicine administration easier and less stressful.

How do I know if my dog has glaucoma?

Signs of glaucoma in dogs include bulging eyes, eye pain, changes in pupils, and thick red veins visible in the whites of the eyes. Glaucoma symptoms are similar to many other eye conditions, so the only way to know for sure your dog has glaucoma is to receive a diagnosis from a veterinarian.

At what age do dogs get glaucoma?

Dogs can have glaucoma at any age. Congenital glaucoma is present at birth, and symptoms are usually seen before the age of one. Primary glaucoma is associated with advancing age in dogs. Secondary glaucoma occurs as a result of a separate eye disease or injury and can develop at any age.

What happens if glaucoma is left untreated in dogs?

Untreated glaucoma will eventually result in permanent damage to the eye and loss of vision. In some cases, the affected eye can rupture due to the dangerously elevated pressure within the eye.