Ensuring the health of your dog as they get older can be a problematic experience, especially with all of the hereditary diseases that dog breeds are prone to. However, one of the most troublesome diseases that your dog can suffer from is glaucoma. It can quickly affect the quality of his life, and make it more difficult for him to get around your home. It can also be quite a painful experience, so taking care of the condition before it becomes a real problem can certainly help your dog feel much better.
If you’ve never heard of glaucoma before or you’re worried that your dog may be suffering from the early stages of this degenerative disease, then you’ll find the information that you need throughout this article.
What is glaucoma?
Glaucoma is a condition of the eye that results in excessive pressure. This is typically caused by insufficient drainage of excess fluid in the eye. Typically, the eye does a good job of regulating its internal pressure in order to remain functioning. However, as a dog gets older, these regulation processes can break down, and the fluid within the eye has nowhere to go.
You may believe that this can’t result in any harm to your dog, but you would be wrong. Increased pressure constricts the blood flow to the eye, causes damage to the optic nerve, and runs the risk of the eyeball actually being damaged.
There are specific dog breeds that are more prone to the eye condition than other dog breeds, such as Siberian huskies, Poodles, Cocker Spaniels, Samoyeds, and Chow Chows.
What makes this condition so serious is that within the first year of the onset of the condition, a dog will lose vision completely in the affected eye. This makes it easy for your dog to have problems getting around, and he may frequently walk into other objects that he isn’t aware of. If you do notice that your dog is having problems navigating the interior of your home, then you should take your dog to the vet immediately so that the condition of your dog’s health can be determined. Waiting too long will result in irreversible damage that cannot be treated.
What causes glaucoma?
The high pressure that is generated within the eye is the result of the impairment of normal outflow of liquid from the eye. This can be the result of the improper development of the filtration angles of the eye or can be the secondary result of some other underlying eye condition, such as the slipping of the lens in the eye, eye tumors, tissue inflammation, or the collection of blood at the front of the eye as a result of injury.
Glaucoma as a result of a secondary infection is a more common diagnosis than the primary onset of the condition.
What are the symptoms of glaucoma?
It is important to know that there are two different kinds of glaucoma: primary and secondary. This means that the signs of glaucoma in dogs can vary depending on which kind your dog has. The sudden onset of primary glaucoma is the least common but the more severe, and is a result of insufficient drainage of fluid from the eyeball. The symptoms of primary glaucoma include:
- frequent blinking of the eye
- recession of the eyeball into the back of the orbit
- high pressure within the eye itself
- redness of the blood vessels within the sclera (whites) of the eye
- a dilated pupil that doesn’t respond to light
- cloudy appearance located at the front of the eye
- loss of vision
Without treatment, the disease can progress even further, and cause the eyeball to enlarge dramatically, and advanced degeneration within the eye, due to the increased damage of the blood vessels and nerves within the eyeball. This can obviously cause your dog a lot of discomfort and should be taken care of as soon as possible by your veterinarian.
Secondary glaucoma is typically the result of a secondary eye infection. You can learn more about what those are in our article about eye infections in dogs. As the eye becomes irritated, there can be a build-up of fluid within the eye in order to provide lubrication to try and rid the eye of the infection. This is less serious, and the underlying condition should be treated in order to eliminate the symptoms and onset of secondary glaucoma. The symptoms of secondary glaucoma include:
- high pressure within the eye
- cloudy appearance at the front of the eyeball
- redness of the blood vessels within the sclera (whites) of the eye
- constriction of the pupil
- debris at the front of the eye that is causing inflammation
- sticking of the iris to the cornea (lens) of the eye
- increased tears
- loss of appetite
- head pressing in order to relieve headaches
- less desire to engage in any kind of activity
What diagnostic steps can be taken?
There are a number of tests than your veterinarian can put your dog through in order to determine whether there is the onset of glaucoma. Keep in mind that a final diagnosis of the disease can be, at first, difficult to arrive at, as the symptoms are very similar to common infections of the eye. It is important that you take note of your dog’s behavior so that you may assist your vet with any questions he may have so that a correct diagnosis can be arrived at before any serious damage has occurred.
The first test that is performed involves the testing of the pressure within the dog’s eye. This is done using a tonometer on the surface of the eye. This is a small device that is used to measure the pressure within the eyeball. It involves a small plastic bead on the head of a pin that is on the device. It gently taps on the eye itself in order to generate a reading of the measurement of pressure.
There is no pain to your dog, as it is done quite gently, and numbing drops can even be added to the eye to make the experience more pleasant for your dog. If it is too high, then your veterinarian will recommend you to an ophthalmologist in order to conduct a more detailed examination of your dog’s eyes.
The veterinary ophthalmologist can conduct tests of his own, including a gonioscopy, where the front of the eye is measured to determine whether any damage has occurred to the optic nerve. Electroretinography is also performed in order to determine whether your dog’s eye will remain blind during the treatment procedure. For secondary glaucoma, X-rays and ultrasounds can be taken in order to determine the source of your dog’s condition.
The results of these tests will help you and your veterinarian determine the best course of action when it comes to treating these degenerative disease or preventing it from spreading to the unaffected eye.
What can be done to treat the condition?
Glaucoma treatment in dogs can vary depending on the diagnosis you receive from your veterinarian. However, the main purpose of any treatment is to prevent it from getting worse or spreading to both eyes. Patience and careful management should be exercised in order to help maintain the quality of your dog’s life, so it’s important that you stick to the daily regimen of treatment provided to you so that the problem doesn’t become more complicated.
In secondary glaucoma, any treatment focuses on the original underlying source of the condition, whether it’s an eye injury, fungal infection or a tumor within the eye. The more quickly this is taken care of, the less chances that the secondary glaucoma will have a drastic effect on the eye.
In primary glaucoma, there is a treatment called cyclocryotherapy. This is the use of extreme cold temperatures to kill the cells that are producing the fluid inside the eye. If used early this treatment can be used to save your dog’s vision, and may even slow down or stop the progression of the condition altogether. Many dog owners have opted for this treatment, but keep in mind that it is not a long-term solution.
There are other medications that your veterinarian may prescribe as well to help reduce the effects of the condition:
- Miotic treatments: drugs that use pilocarpine have been quite effective in treating glaucoma in dogs. How it works is that it shrinks the pupil within the eye, which then allows fluid to flow out through the canal. This, in turn, relieves the pressure within the eye in order to prevent further damage from occurring. Miotic treatments should not be used if your dog is suffering from uveitis (inflammation of the middle area of the eye) or lens luxation (pushing of the lens through the pupil into the front of the eyeball). This is a topical treatment.
- Beta-blockers and CAI diuretic: although typically recommended for heart conditions, beta-blockers work quite well on reducing the symptoms and progression of glaucoma. CAI (carbonic anhydrase inhibitor) diuretic also does the same thing. They both reduce the production of fluid within the eye so that the pressure isn’t built up to begin with. Both are topical treatments.
- Osmotic diuretic: this solution can be provided in IV form or oral, and dehydrates the vitreous tumor in the eye. This is the clear gel that fills the space between the lens and retina within the eye, and makes up a large portion of the eyeball. By dehydrating it, it shrink in size and reduces the pressure within the eyeball.
- Corticosteroids: these multi-purpose medications focus on reducing inflammation throughout the body, and the eye is no different. Applied topically, it can help to reduce swelling within the eye and helps to minimize the reddening of the sclera from the affected blood vessels in the area. Care should be taken during application, as corticosteroids have been known to have a few side effects in dogs.
In the most extreme cases where the eye cannot be treated, surgical removal of the eyeball is a viable option. The eyelid itself will be sewn closed in order to prevent bacteria from getting into the empty eye socket. It may be strange at first for your dog to only have one eye, but he will adapt quite quickly and learn to maneuver properly with his new impairment.
If the condition is caught early and treated before any drastic effects have taken place, you will need to schedule regular appointments with your veterinarian in order to check the pressure of your dog’s eyes. The intake of your dog’s medication will also be assessed to ensure that it’s actually working and that there are no interactions with anything else your dog could be taking. Even if your dog has his eye removed due to glaucoma, the quality of his life can still be maintained as long as activity and play is done more carefully in order to avoid injury
Preventing glaucoma before it starts
In order to minimize your pet’s risk of the disease, there are certain steps you can take to improve the health of his eyes. Special additives, such as beta-carotene, vitamins E and C, and some substances such as lutein and rutin can be added to his diet in order to reduce the damage that can occur within the eye. The elimination of specific objects of stress within the home can also reduce the pressure that is built up within the body.
Stress leads to oxidative damage that can occur within the body, especially the dog’s eyes. Pressure to the dog’s neck should also be eliminated, so a loose collar or harness improves the flow of fluids within the body and doesn’t place added stress on your dog.
As your dog gets older, it’s important that you take the necessary steps to ensure that his health is not declining. Schedule a certain time every day to examine your dog’s eyes, and take note of any changes that come to your attention. A change in behavior is also a good sign to look out for, and should be brought to your vet’s attention immediately.
It can be difficult to know what you should be looking out for, as some of the easier signs to see usually indicate that it may be too late to avoid blindness in an affected eye. However, by treating this degenerative disease and finding an option of care that works well for your dog, you can ensure that his quality of life doesn’t get worse. However, do not fear if your dog does go blind from this disease. You can learn how to easily take care of and adapt your lifestyle to accommodate a blind dog.