January 09, 2013
Dr Rex Riggs talks today about eye issues in cats and dogs. It's certainly not something I think much about but he's right - we need to do eye checks on our pets too.
“An animal's eyes have the power to speak a great language.”
This quote by Martin Buber an Austrian-born Jewish philosopher is a favorite of mine. Anyone who has owned a Labrador or Golden, or any dog for that matter, knows what I am talking about.
We all know how important eyes are in everyday life; it is true for us, as well as our pets. Now after saying that, pets have an amazing ability to thrive with what they are given. Blind dogs and cats often live happy lives, as long as you don’t rearrange the furniture every week. They just don’t seem to have the psychological worries and anxieties of being blind. My goal is to give you insight (insight… get it?) into how we can take better care of our companion’s eyes.
Let’s start first with the cat’s eyes.
Ever wonder why cats have a vertical elliptical pupil in the dark? It allows them to see the little creatures they are stalking better by letting more light get to their retinas, not that I want them to hunt little creatures outside ( see my previous blog post on Indoor vs Outdoor Cats).
The most common problem we see with cat’s eyes in recurrent conjunctivitis. The conjunctiva is the pink tissue surrounding the eye. Cats are often infected when they are young. We have all seen those crusty eyed snotty nose little kittens. The most common causative agent, by far, is a herpes virus. Obviously it is a different herpes virus then humans get, but all herpes viruses have similar traits. Herpes hides in the nerves and when the animal is stressed the herpes can become active.
You can never cure a cat of herpes, but it can be controlled. One tool we have is called L-Lysine, which is an amino acid powder you sprinkle on the cat’s food. Herpes needs another amino acid called Arginine to replicate, and the Lysine will substitute itself for the Arginine and decrease the number of outbreaks. In active infections, antibiotics will do nothing against herpes infections, so we often need to use antiviral drops such as Idoxiuridine. These drops need to be compounded at a pharmacy, and as Laura mentioned in her Eye Care post, can be a little pricey.
We can also see scratches and ulcers on both cat’s and dog’s corneas. Any of you contact users can attest, corneal ulcers hurt like a bear! Your pet will often squint and rub their eye. If you see your dog or cat squinting their eyes, they most likely will have an ulcer. These need to be treated early to prevent scaring. Don’t wait on eyes!
The most common cause of corneal ulcers is trauma, from a nail, twig or any number of things. I had a dog come in for a second opinion on a recurrent eye ulcer, which would just not heal. I put some topical anesthesia drops on the eye and looked under the third eyelid… and there was an old cat’s nail that had been in there for weeks! We removed the nail and the ulcer healed in 48 hours. So make sure your vet looks behind the third eyelid. Any foreign body can be hiding there.
We use fluorescing stain to diagnose corneal ulcers. The cornea is made of two main layers. The top on is made up mostly of water and the second layer is more of a fatty layer. The fluorescing stain only stains the fatty layer. So if there is no scratch, it just rolls off. If an ulcer is present, the second layer has been exposed, and the dye binds to it and will show up as a bright green area. Most ulcers heal within 24 to 48 hours when the cells of the cornea migrate towards each other until the defect is closed. We often use ointment to protect the eye while that happens. Some corneas have indolent ulcers, which don’t heal. With these we need to roll back the edges of the ulcer, and make a grid with a needle on the cornea for it to heal. This often only requires topical anesthetic agent.
Glaucoma. Did you know dogs get glaucoma? Well they do, and it is something that should be measured by your vet at your animal’s annual exam. Glaucoma is an increase of pressure in the eye. It is a silent disease, and it can rob your pet of his/her sight without you knowing it. Certain breeds, such as Cockers, Beagles Basset hounds and Goldens are more prone to the condition. It is a controllable condition, so don’t worry, but get your dog’s eye pressures checked when you are at your vets, and also have your own pressures checked on your annual eye exam.
Cataracts are another problem we see. It is an opacification, or clouding of the lens inside the eye. When this happens the light cannot get back to the retina effectively, and thus the animal will have a reduction in vision. This should be distinguished from lenticular sclerosis, which is the graying of the pupil you see in older animals. This is a normal aging change and does not affect the animal’s vision. You can tell the difference because if you look at a cataract it looks like chipped glass, and lenticular sclerosis just looks grey. Cataracts can be congenital/hereditary or most commonly in dogs, the cause is diabetes. Cats don’t get diabetic cataracts. Cataracts surgery is common in veterinary medicine and is very successful but not cheap…except if you had insurance!!
Well I could go on forever about eyes, and some of you are now saying I already have. The take-home is to care for your pet’s eyes as well as you take care of your own. If you don’t get an annual eye exam yourself….. then take BETTER care of them than you do of your own.
January is Eye Care Month at Embrace Pet Insurance
Guest Post: Common Eye Issues as seen by Dr Rex Riggs
Podcast: cat and dog eye questions with Dr Patrick Mahaney
Claim Example: Dog Cataracts
Other posts by Dr Riggs