What is Glaucoma in Dogs?

Introduction

For Bella, her spirited Labrador Retriever, Max, had always been the perfect companion. She cherished their daily walks and playtime in the park. But one day, she noticed that Max was bumping into objects and seemed disoriented. Concerned about her beloved pet’s sudden change in behavior, Bella took Max to the veterinarian for a comprehensive examination. The vet diagnosed Max with glaucoma, a serious eye condition that can affect dogs.

Glaucoma is an ocular disorder characterized by damage to the optic nerve. This causes loss of vision and, eventually, blindness. In addition, in some cases, it can cause pain. It is estimated that approximately 40 percent of dogs will develop Glaucoma in one or both eyes.

Types of Glaucoma in Dogs

Dog can suffer from different types of eye problems such as corneal ulcers, conjunctivitis, uveitis and infections, There are many types of Glaucoma, including primary open-angle glaucomas, normal tension glaucomas, congenital glaucomas, juvenile open-angle glaucomas, and pigmentary glaucomas. However, the most common form of Glaucoma is primary open-angle Glaucoma.

Primary Open-Angle

Primary open-angle Glaucoma (POAG), also called primary angle closure glaucoma, is the most common form of Glaucoma. It occurs when fluid builds up behind the iris, blocking fluid flow into the eye. The optic nerve is damaged as the pressure increases, causing vision loss.

It affects both eyes equally, although it usually starts in one eye and progresses over time. POAG is typically diagnosed based on symptoms, including painless blurring of vision, increased sensitivity to light, decreased peripheral vision, and halos around lights.

Normal-Tension Glaucoma

Normal-tension Glaucoma (NTG) is a type of Glaucoma that affects older dogs. NTG causes damage to the optic nerve, which leads to vision loss.

It’s important to understand that NTG differs from other Glaucoma types because it occurs in normal eyes. While other forms of chronic Glaucoma require elevated pressure inside the eye, NTG does not. Instead, it’s caused by increased fluid pressure within the eyeball.

Because NTG is a condition that develops over time, early detection is critical. Fortunately, several signs indicate that your dog could develop NTG. These include:

• Excessive tearing
• Redness in the eye
• Loss of vision
• Blind spots in the field of view
• Licking his face

Congenital Glaucoma

Congenital Glaucoma is a condition that causes damage to the optic nerve and vision loss in puppies. It occurs when fluid builds up inside the eye, causing pressure to build up behind the lens. This pressure damages the optic nerve, which carries visual signals from the eyes to the brain. As a result, the puppy loses sight.

There are two types of congenital Glaucoma: primary and secondary. 

• Primary congenital glaucomas are caused by genetic mutations that affect the development of the iris, ciliary body, trabecular meshwork, and retina.
• Secondary congenital glaucomatous conditions are caused by other diseases that affect the eye, including trauma, inflammation, tumors, infections, and hereditary disorders.

Primary congenital Glaucoma usually appears within the first few weeks of life, and secondary congenital Glaucoma typically occurs after the pup has developed a robust immune system. Both forms of congenital Glaucoma are treatable, but early detection is critical to prevent permanent blindness.

Juvenile Open-Angle Glaucoma

Juvenile open-angle Glaucoma (JOAG) is a common canine glaucoma affecting young dogs. JOAG occurs when fluid builds up inside the eye, causing damage to the optic nerve.

Glaucoma usually develops during puppyhood, although it can develop later in life. Symptoms typically appear within two years after birth, and affected puppies may experience vision loss, blindness, and other symptoms.

Pigmentary Glaucoma

Pigmentary Glaucoma is a common eye condition in dogs, and it causes damage to the optic nerve, which is responsible for transmitting visual signals from the eyes to the brain. As a result, vision becomes blurry, and the dog loses sight.

Although pigmentary Glaucoma usually affects older dogs, it can happen at any age. There are two types of pigmentary Glaucoma: primary and secondary.

• The primary pigmentary glaucomatous disease occurs when the iris thickens and becomes opaque.
• Secondary pigmentary Glaucoma develops when the lens reduces and blocks light from reaching the retina.

What Causes Glaucoma in Dogs?

Glaucoma in dogs is most often caused by a blockage or narrowing of the fluid pathway that drains typically fluid from the eye. Other causes can include trauma to the eye, tumors, inflammation, and inherited tendencies. When these abnormalities occur, pressure builds in the eye due to too much fluid collecting in the anterior chamber. This pressure can damage and eventually destroy all parts of the eye, including the delicate nerve pathways.

Even though breed-specific traits can increase a dog’s risk for developing glaucoma (e.g., Shih Tzu), any dog can be afflicted by this condition regardless of age, size, or breed. In some cases, genetic predispositions may play a role in glaucoma development; however, animal studies have found that specific biochemical processes associated with aging may contribute more significantly to this condition than genetics alone do.

Symptoms of Glaucoma in Dogs

Glaucoma in dogs is a severe eye problem, and it’s essential to know the symptoms to recognize it quickly. The main sign of glaucoma in dogs is pain, which may be evidenced by excessive blinking and tearing of the eyes. Your dog will also be more sensitive to light if they have glaucoma.

In addition, due to the increased pressure inside their eyeballs, your dog may lose their vision if they suffer from glaucoma. Visual impairment can manifest as cloudy eyes, an enlarged pupil, or loss of peripheral vision. Finally, your pup’s eyes may appear more prominent than usual if they have glaucoma, and this is because their cornea is thicker due to the increased pressure in their eye caused by the condition.

If you notice any of these symptoms in your pup, you must consult a vet immediately for proper diagnosis and treatment.

Diagnosing Glaucoma in Dogs

Diagnosing glaucoma in dogs is a complex task. But by understanding the Symptoms, veterinarians can begin to consider the possibility of glaucoma. If your vet suspects glaucoma may be present, they’ll need to perform several tests to diagnose it accurately.

The first test that will be performed is an eye exam where the vet uses unique tools and dilates the pup’s pupil to view their retina and optic nerve, which can provide critical clues as to whether or not glaucoma is present due to signs of narrowing or swelling of said tissue. They’ll also run tests that measure intraocular pressure, which could indicate high levels due to fluid accumulation from glaucoma.

Finally, your vet may order imaging tests like digital X-rays, ultrasound scans, or Magnetic Resonance Imaging (MRI) for more detailed information. All these tests, combined with a regular physical checkup, are used to detect and accurately diagnose Glaucoma in dogs. So it’s essential to get expert advice from a veterinarian if you suspect your pup has Glaucoma.

Treatment for Glaucoma in Dogs

Medications are typically used to treat Glaucoma. However, some cases require additional treatment, such as surgery. In addition, there are times when medicine alone isn’t enough, and surgical intervention is needed.

• Laser therapy is one option for treating glaucomas in dogs. A fiberoptic probe delivers a small amount of energy to the eye, stimulating cells in the trabecular meshwork and causing them to produce substances that reduce intraocular pressure.
• Filtering surgery is another method for lowering intraocular pressure. Small incisions are made in the sclera, allowing drainage tubes to be placed under the iris. These tubes allow fluid to drain out of the eye.

Stents are implanted into the Schlemm’s canal, and they help keep the channel open and prevent fluid buildup.

• Cyclodestructive procedures involve destroying a part of the ciliary body. This reduces the production of aqueous humor, which helps lower intraocular pressure.
• Enucleation is routinely performed for glaucoma where medical management fails and other surgical options are not.

Repeat surgical treatment may be necessary if the condition doesn’t respond well to initial treatments or if the disease progresses.

How to Prevent Dogs From Having Glaucoma

Fortunately, you can take steps to prevent glaucomatous conditions in your dog.

• Make sure your dog has regular eye exams.

Your dog must receive regular eye examinations. Regular eye exams allow your vet to monitor your dog’s eyes for signs of Glaucoma, and early detection permits your veterinarian to treat the problem before irreversible damage occurs.

• Feed your dog foods rich in omega fatty acids.

Omega 3 fatty acids are found in fish oils and flaxseed oil. Omega 3 fatty acids are vital for maintaining normal ocular health. In addition, they are needed for proper cell membrane formation and maintenance.

• Limit your dog’s exposure to sunlight.

Sunlight contains ultraviolet rays that can damage your dog’s cornea. Exposure to these rays can cause cataracts and retinal degeneration.

• Provide adequate nutrition.

A diet low in carbohydrates and high in protein helps maintain healthy eyes. Conversely, high carbohydrate diets can contribute to elevated intraocular pressure.

• Avoid medications that contain steroids.

Certain medications used to control inflammation can affect the production of tears. These include corticosteroids.

These drugs should be avoided to avoid increasing intraocular pressure.

• Reduce stress levels.

Stress can play a role in causing Glaucoma. Stressful situations such as moving, traveling, and separation anxiety can trigger episodes of acute Glaucoma. Dogs that suffer from chronic stress often develop Glaucoma. You can give your dog plenty of exercise and attention.

• Exercise regularly.

Exercise promotes circulation and keeps your dog’s muscles toned. Exercising daily reduces the likelihood of developing Glaucoma. Give your dog plenty of opportunities to run, jump, swim, and chase balls.

• Monitor your dog’s behavior.

Behavior problems such as aggression, fearfulness, and hyperactivity can indicate the early stages of glaucoma development. If you notice behavioral changes in your dog, please contact your veterinarian immediately.

• Take precautions when grooming your dog.

Grooming your dog too frequently can cause irritation and inflammation of the eyelids, leading to tearing and discharge.

Limit your dog’s grooming sessions to once every two weeks

Frequently Asked Questions