March 1, 2021

Medical Issues Wellness & Prevention

Glaucoma in Pets – Symptoms and Treatments

by Aili V. Heintz, DVM

Today, we are going to focus on an eye condition referred to as glaucoma. We will address the following:

  • what glaucoma means,
  • the most common signs and symptoms,
  • which pets may be more likely to get glaucoma,
  • treatment options, and
  • what we can do together to help try to monitor for and prevent glaucoma.

Many eye conditions can be very painful both for people as well as for pets. Unfortunately, pets often can’t tell us when something is starting to feel “not right.” This is why we need to be aware of the little signs that may be warning us that something bigger is happening.

What is Glaucoma?

Glaucoma simply refers to the disease process in which the pressure inside the eye becomes elevated.

Think of the eye like a basketball. There is an ideal amount of air that you pump into the ball so that it bounces the best and “works” well.

If you keep pumping in more and more air, there is nowhere for it to go since the ball only has a limited amount of space. Pump the ball up too much, and it can pop because of all the pressure.

This is similar to the eye since it, too, is an enclosed structure. Too much pressure and the eye becomes overly distended and painful. In some cases, the eye can eventually rupture.

What causes glaucoma?

There are two main types of glaucoma: primary and secondary. To understand these better, you must first know that inside the eye there is a gel-like liquid called aqueous fluid.

This aqueous contains nutrients and oxygen for the different parts of the inside of the eye. The pressure inside the eye remains steady as long as the amount of aqueous being made is equal to the amount of liquid being absorbed or drained.

Primary Glaucoma: This form occurs in a healthy eye and often occurs due to an inherited abnormality of the absorption/drainage angle within the eye. This causes pressure to build up because fluid is not able to be circulated in the eye as normal.

Secondary Glaucoma: This form occurs secondarily to some form of eye disease or trauma/injury to the eye. The most common causes of this type of glaucoma include tumors that block fluid flow within the eye, infections/inflammation inside the eye that can cause abnormal scar tissue, damage to the lens of the eye, and bleeding inside the eye.

Why is Glaucoma bad?

Going back to the basketball analogy, the eye only has so much room to accommodate extra pressure. As the pressure increases, it can cause damage to the retina and the optic nerve. This damage can cause irreversible vision loss. We only get two eyes, and once one is damaged, you cannot simply “replace” it. In addition to this, it can be very painful!

Are certain pets at a higher risk of getting glaucoma?

Yes, there are certain breeds that are more likely to develop glaucoma. These include:

  • Boston terriers,
  • Akitas,
  • Malamutes,
  • Poodles,
  • Italian greyhounds,
  • Terriers,
  • Beagles,
  • Pugs, and
  • Many more.

There is actually quite a long list of breeds that are predisposed to glaucoma. If you are concerned or want to know if your dog’s breed is on the list, please consult with your veterinarian. Although I have listed only dogs, cats can also get glaucoma.

What are some signs that I should be watching for?

Signs of glaucoma to watch for include:

  • Holding the eye closed,
  • Rubbing the eye,
  • Sensitivity around the eye or face,
  • An elevated 3rd eyelid,
  • The physically enlarged appearance of the eye,
  • Increased watery eye discharge,
  • Cloudy or blue appearance to the eye/cornea,
  • Increased redness to the white portion of the eye,
  • Decreased activity or lethargy, and
  • Loss of vision.

These signs can occur rapidly or may have a slower onset depending on the cause of glaucoma. If you see these signs in your pet, please get in for an exam ASAP. These symptoms can be seen with other eye problems as well, so these signs do not guarantee that glaucoma is the problem. A rapid diagnosis is key with eye issues.

How will my vet know if my pet has glaucoma?

Your vet will do an exam to evaluate the eye first. If she is concerned that your pet may have signs of glaucoma, she will then test your pet’s eye pressure using a tool called a tonopen.

A tonopen is a small device that allows the vet to gently touch the outside surface of the eye and get a measurement of the pressure inside the eye. This is a non-invasive test and does not hurt your pet.

Are there any treatment options for glaucoma?

Yes! Glaucoma treatment typically involves long-term eye drops that help reduce eye pressures. Your vet may also use pain medications to help to keep your pet comfortable, especially right after diagnosis.  The doctor will want to closely monitor your pet’s eye pressures while he is on these medications, and she will want to check his eyes frequently. 

There are times when medications alone may not be enough to reduce your pet’s eye pressure. In some cases, surgical procedures from a veterinary ophthalmologist may be needed to try to help save the eye. When glaucoma doesn’t respond to treatment, the eye may need to be removed. This option is only done as a last resort! (You would be surprised how well they do with this procedure! I used to have a one-eyed dog and most people never even noticed).

What can I do to try to prevent glaucoma?

The best form of prevention is being proactive! While you can’t necessarily predict whether or not your pet will get glaucoma, you can do routine eye pressure checks at your vet visits. Remember the test is not invasive or painful, and it is easy to do for your pet at any visit. Early detection is the key to help keep your pet’s eyes comfortable and healthy. Ask your vet to add this easy test as part of your pet’s wellness exam!

Eyes are often described as windows to the soul and we are only given two. It is so important to keep those eyes healthy. Monitoring and watching for signs of eye problems along with routine wellness exams are important tools for helping to ensure a happy and comfortable life for your pet.

Dr. HeintzDr. Heintz is a small and exotic animal veterinarian at Countrycare Animal Complex in Green Bay, WI. She earned her Doctor of Veterinary Medicine from the University of Illinois – Urbana/Champaign. Her passion is helping all animals, whether furry, scaly, or feathered, lead long and healthy lives.