"Nictitans Gland Prolapse" is the clinical definition for Cherry Eye in dogs. Dogs have a gland in their eyes that produces about 35% of the tears needed to keep their eyes moist. It's often called the 3rd eye-lid.
Cherry Eye is what happens when the gland "prolapses" which means that it comes disconnected from the tissue that's supposed to keep it in place.
When that happens, it becomes inflamed, which means swollen and irritated, and usually turns a red color.
The 3rd eye-lid gland detaches from the rest of the eye because of a weakness in the tissue that's supposed to keep it attached.
Experts don't know exactly why some dogs tissue is weaker than others, but there are a few breeds that seem to be more prone to it:
Symptoms of Canine Cherry Eye are pretty straight forward. You will actually be able to see the gland protruding (sticking out) from the inside corner of your dogs eye.
You also might notice a discharge from the effected eye, as well as your dog pawing or scratching at it.
Diagnosis of Cherry Eye is also pretty straight forward. Your veterinarian will do a physical exam of your dog's eye, and also check for any infection.
Unfortunately the only effective treatment for canine Cherry Eye is surgery, but it is simple.
It's a matter of reconnecting the gland back to it's original position, and the success rate for this surgery is about 90%.
In some cases the gland may need to be removed completely, but that will result in a dog suffering from dry eye for the rest of his life.
A dog may also need to be treated with an antibiotic if the eye also has an infection in it. The most common antibiotic used for treating these kinds of infection is Ciprofloxacin.