Imagine one day you’re on the floor playing with your dog and you notice she’s pawing at her eye. You don’t think much of it. In fact, when she rubs her eye against your leg, you think she’s just being a mush.
But then, as the day goes on, your baby doesn’t seem interested in playing, eating, or doing much of anything.
Your reaction is probably not much of a reaction at all. You’re likely thinking, “Hmmm…let’s see how she is tomorrow.”
There are some conditions, illnesses, disorders, that demand immediate attention— and glaucoma is one of them.
The signs can be subtle and sometimes nonexistent. That’s the problem with glaucoma. Before you realize there’s anything wrong, your dog is irreversibly blind.
What is Glaucoma?
Glaucoma is increased pressure in the eye. Here’s how that happens.
The cells of the eye produce a fluid called aqueous humor. This fluid is different than tears. Aqueous humor nourishes the tissue inside the eye and it maintains the shape of the eye.
Tears, on the other hand, bathe and protect the outside of the eye.
In a normally functioning eye, the aqueous humor drains out of the eye and into the bloodstream through a sieve-like area called the drainage angle. Meanwhile, the cells of the eye are producing more aqueous humor.
When there’s a balance between aqueous production and drainage, eye pressure is normal. But when the drainage angle becomes partially or completely clogged, the pressure builds. This is the onset of glaucoma.
Primary vs. Secondary Glaucoma
There are two different forms of glaucoma; primary and secondary. Knowing which one your dog has is critical if treatment’s going to be effective.
With primary glaucoma, the pressure buildup is a genetic predisposition causing either the drainage pores to be too small or narrow drainage angles.
Some breeds are prone to this. The Beagle, Cocker Spaniel, Basset Hound, Chow, Shar Pei, Jack Russell Terrier, Shih Tzu, Siberian Husky and Elkhound all seem to be genetically predisposed to glaucoma.
Interestingly, cats rarely suffer from primary glaucoma, though they can have secondary glaucoma.
When a dog has primary glaucoma, one eye is usually affected months before the other. Both eyes are not usually affected at the same time.
Secondary glaucoma is brought on by another condition like a wound to the eye, scar tissue that closes the drainage angle, bleeding in the eye, inflammation, displacement of the lens, a tumor, an infection or anything else that could cause a narrowing of the drainage angle.
In cats, secondary glaucoma is almost always caused by a condition called chronic uveitis, which will be next week’s blog topic.
Regardless of the cause of glaucoma, the buildup of pressure will destroy the cells of the retina and the optic nerve. The damage may be irreversible if it continues for too long, meaning permanent vision loss, and potentially blindness.
It’s so important to know the signs of glaucoma so you can act fast. As soon as you detect a problem, you must get your dog to the vet or you risk your dog losing their eyesight.
The Signs of Glaucoma
The signs of glaucoma are so subtle blindness may set in before you recognize there’s a problem. But knowledge is power…if you know what to look for you’ll be in a better position to act quickly.
Here are some symptoms:
Pain – Your dog will have a migraine-like headache…but they can’t tell you that. They may paw at their eye or rub against the furniture…but they may not. They may squint one eye or flutter their eyelid…but they may not. The point is, be on the look out for other signs of pain, like a lack of appetite or disinterest in activity.
Dilated pupil – The pupil may become larger in one eye than the other since usually one eye is affected at a time.
Cloudy cornea – A healthy cornea is usually clear and invisible, but increased pressure will initially stretch the cornea and tear the protein fibers of the cornea making it look cloudy. Then as the pressure gets worse, the fluid buildup in the cornea exacerbates the cloudiness.
Bloodshot eye – If the whites of the eye look red, the blood vessels are starting to be affected. At this point your dog’s vision may already be lost.
One enlarged eye – The pressure will eventually cause the eye to look enlarged and may cause it to protrude.
Any of these signs is immediate cause for concern. See the vet quickly…not tomorrow or next week. But immediately!
Left untreated, glaucoma will cause blindness and a permanent enlargement of the eye. The pressure must be controlled fast.
Your vet will do an initial evaluation but if they suspect glaucoma, they’ll send you to a veterinary ophthalmologist. This is a condition that requires expertise.
If you suspect your dog is suffering from glaucoma and your vet doesn’t recommend an ophthalmologist, seek one out on your own.
The eye doc will test the pressure in the eye. In a normal dog, it will be between 10 and 20 mmHg. With glaucoma, it’s often between 30 and 50 mmHg.
The vet will determine if it’s primary or secondary glaucoma. Secondary glaucoma requires treating the underlying condition. If that’s an infection, they’ll prescribe antibiotics. If that’s a tumor, surgery may be necessary.
But first and foremost, the treatment plan will reduce the pressure and the amount of fluid produced, increase drainage of the fluid, and provide pain relief.
Most of the treatments for glaucoma are topical ointments, but some are oral meds. Unfortunately, though, these treatments aren’t long-term solutions. Surgery is often the only long-term fix. And what type of surgery depends on whether or not this condition has already permanently affected your dog’s eyesight.
With primary glaucoma, your greatest hope is to minimize pain and save the vision in the unaffected eye. Vision is often lost in the first eye because glaucoma comes out of left field. Onset to diagnosis is not usually quick enough.
But once you know your dog suffers from primary glaucoma, you can be much more proactive in protecting your dog’s remaining eye.
The eye doctor can test to see the likelihood of your dog getting glaucoma in the other eye. And you’ll know what the signs are so you can get treatment fast if it happens.
Removing the Eye
Regardless of why or how your dog ended up with glaucoma will seem irrelevant to you if they are permanently blind.
If they’re blind, you’ll have to make the difficult decision whether or not to remove your doggie’s eye. This seems frightening. But an enlarged, blind eye with glaucoma is painful to the dog.
Dog’s are remarkable creatures. They adjust well to living with one eye. And they’re not vain, so how it looks will only matter to you. But you’ll love them no matter how they look, and you’ll be glad they won’t be in pain.
So keep an open mind if this is your vet’s recommendation.
Do you have a dog that lost their sight to glaucoma? What treatment option did you choose? You may be able to help someone else going through this with their doggy. Please share your experience in the comment section above.