Understanding Cherry Eye/The Third Eyelid

Humans, dogs and cats have a lot of features in common. We share many of the same reactions to stress and pain, but there is one thing that cats, canines and most other animals have that we don’t, and that is the third eyelid.

What is the third eyelid?

Well, medically it is known as the “nictitating membrane.” In English it is an eyelid that provides extra protection for the eye. Rather like the wiper on our windshield. Our windshield wipers are usually connected to a container of water to clean our windshield, the third eyelid contains a gland that provides tears to keep the eye moist, among other things. It also provides antibodies and an enzyme that can inactivate bacteria.

What is Cherry eye?

Cherry eye is a condition that affects dogs usually during their first year.

There are some breeds, more than others that are effected by this condition: Cocker Spaniels, English Bulldogs, Mastiffs, Basset Hounds, Beagles, Boston Terriers, Lhasa Apso, Pekingese and Pugs are the most affected breeds. However, it can happen to any dog.

In my opinion it is ugly and scary, though it looks worse than it is. It is a red looking bump that seems to be growing out of the corner of the dog’s eye and you feel like it is going to “pop out” at any moment. Of course, it is not..

Most doctors say it is a congenital defect in the ligament that holds the gland of the third eyelid in place. It can be surgically repaired, however sometimes the surgery doesn’t hold the gland in place and it comes back up for all to see. Seeing it does not mean that it is not functioning, it just means it is not pretty to look at. Removing the gland if surgery can’t hold it in place is not recommended as this gland produces tears necessary for your dog’s eye. Without it your dog can suffer from “dry eyes” and that can be very painful.

The interesting thing is, if surgery does not hold the gland back in place and it pops up, time can work on your side as the “cherry eye” may decrease in size.

Even though this gland only supplies about 30 percent of the eye’s tear production, keeping it, no matter how bad it may look, is insurance for your dog’s eyes. It is tears that help keep the cornea of the eye healthy. The cornea has no blood vessels of its own, so the oxygen and nutrients that are supplied to it come through the tears.

Cherry eye is not known to be painful, but it can be irritating to the dog and what do dogs do when something irritates them. They scratch and it is the scratching that can cause problems that lead to eye injuries.

Today with the advent of many new techniques in veterinary surgery most of the time, positioning of the gland is successful. When a problem arises, there are other “tricks” a surgeon can perform that will remedy the problem.

On the positive side, this condition is not a “life or death” type of a situation. It can go unattended for a while, though cosmetically it bothers you more than the dog, it really needs to be attended to.

There is nothing you can do to prevent this from happening, but there are safe and effective ways to fix the problem.

Now what has this to do with cats?

Cats have a third eyelid, too. It sits for the most part on the inside corner of the eye. You might even see a bit of it peeking through.

Cats do not get “cherry eye.” However, if they are really ill or under a stressful situation the eyelid will start to cover the eye.

I have 10 year old feral cat, Mr. Boots, that did not have a chance to have a life as a treasured kitten. He came into our lives as a 10 week old kitten (more or less) and whatever conditioning had been in his past life had already made a mark on him forever.

Several years ago our “grandfather cat” died. Mr. Whiskers ruled the household and the other cats with a gentle but stern hand. His death then allowed our second in command cat, Isaac to be in control of the rest of the cats. Isaac became a tyrant and poor Boots shivered in his boots. The stress caused the third eyelid of his left eye to cover his eye and I became panic stricken.

The cat was scared to death of Isaac (and so was everyone else) so to make a long story short, Mr. Isaac packed his bags and went on to become a “nursery mouser” at a friend’s plant nursery.

Peace was restored and within a few weeks the third eyelid retracted back into its normal shape and life went on (well, sort of.)

The third eyelid in a cat functions the same as in a dog, keeping the “windshield clean. However, it only appears in time of serious stress or illness. If the third eyelid appears and stays around for a few days, please take your cat to the vet even, if the cat does not appear to be ill.

The Burmese cat is the breed most often affected by this condition.

As always, if your pet has any sign of not feeling well or is acting out of character, please call or see your vet. An ounce of prevention can save many veterinary dollars.

Motherhood not only brought me a boundless supply of children, it also filled my life with many animal critters that gave me an opportunity to learn much. Sharing some of this knowledge that I have learned through the years has become part of the "fun" I call my life. For other interesting stuff come and visit me at http://www.cats-and-dogs-on-the-web.com