Cherry eye is a common term for a prolapse of the third eyelid (nictitating membrane) of dogs. This eyelid contains a tear gland that promoted oxygen supply and is responsible for a portion of the tear production of the eye. When working properly, the third eyelid is tucked away and can't be seen. However, when the anchoring tissue is not working correctly, this third eyelid can protrude, producing a very red lump in the inside corner of the eye. While it's not usually painful for dogs, it is unsightly for humans to look at.
What Causes Cherry Eye?
It is not fully understood what causes cherry eye. The prolapsed gland can be caused by scrolled or cartilage turned outward in the third eyelid, abnormal cells, or a prolapse of fat in the eye. There is likely a genetic causation as well. Cherry eye can affect one or both of a dog's eyes. However, it doesn't happen in both eyes at the same time. Cherry eye can occur very suddenly. Your dog may look perfectly normal and a few minutes later, there will be a large red tissue that is protruding from their eye. This condition can affect any breed but it is more common among the following:
How a Dog May React to Their Cherry Eye
A dog with a cherry eye will likely be uncomfortable. They may be impacted by eye dryness, swelling, irritation, inflammation, and pain. It's common for dogs with a cherry eye to paw at the eye and rub their face on the floor, furniture, or other things to relieve their discomfort. It's best to seek medical attention right away.
Diagnosing Cherry Eye
The owner is usually the first to notice the cherry eye in their dog and a visual diagnosis by a veterinarian will confirm this. Advanced testing may be administered if a veterinarian thinks cancer or other conditions may also be present, but otherwise, no invasive tests are needed to diagnose cherry eye.
Treatment for Cherry Eye
Treatment can involve one of two options. The first involves returning the eyelid to its proper location and try to save the gland (approximately an 80 percent success rate). The second option is a surgical procedure to remove the eyelid and the gland or a surgery to reposition the gland. A risk of removal includes dry eye later in life, which can potentially lead to damaged vision. This can be controlled with medication, but it's better to prevent the situation in the first place. Usually, the third eyelid is only removed if the gland has been damaged by prolonged exposure. Therefore, it's important to have your pet assessed sooner rather than later. Discuss the options with a trusted veterinarian to determine the best course of action.
The non-surgical option usually includes trying a steroid ointment to coax the gland back to its normal position and antibiotics to prevent infection within the eye. If that doesn't work, surgery is the only option. The current treatment of choice is a surgical repositioning rather than removal of that gland. Many different surgical repositioning techniques have been reported and the technique will vary based on the veterinarian, dog breed, and each specific case. For example, one successful surgical approach is the technique which involves tucking the gland down into the conjunctiva. The only risk is the possibility that a small piece of suture will rub the cornea, and that's easily remedied by removing the suture. Tacking the gland to the edge of the eye socket has a high failure rate due to the potential for long-term problems.
Life After Cherry Eye Surgery
Most of the time, the surgery is very successful in correcting cherry eye. After the operation, the affected eye will return to normal function, as long as the gland was repositioned. If it was removed, the dog will need eye drops to provide necessary lubrication to the eye. It will need these for the remainder of its life. Even if your dog undergoes surgery in one eye for a cherry eye, there is no guarantee they will not develop it in the other eye. There are no current medications or surgical procedures to prevent cherry eye in dogs.