Cherry Eye

This is the season for new puppies. There are more than a few households in the area that are starting the housetraining, “no biting”, and “hey, put that down” training. Along with the excitement of teaching your new puppy how to be a good citizen comes the occasional health worry too. Today I am going to talk about a problem that we see occasionally in puppies that many people have not heard of--Cherry eye.

Over the next few months I am expecting a few patients to appear with their new owners nervously wringing their hands, understandably concerned about that big pink blob that has suddenly appeared in the inside corner of their little dog’s eye. Even though it doesn’t seem to be bothering the dog much there is something clearly wrong. Is it a tumor? Is the eye going to explode? What is that thing?

Cherry eye, as that little pink blob is commonly called, or prolapsed gland of the nictitans if you want to be more official, is a misplacement of one of the glands around the eye that is responsible for making some of the components of normal tears. Normally the gland sits quietly under the lower eyelid, resting near the bridge of the nose. It is held in place partly by the cartilage that helps give structure to the third eyelid, and partially by a fibrous tether that pulls the lower edge of the gland down deeper into the socket. If the gland becomes visible, popping up over the top of the lower lid, it means the fibrous attachment that should be holding it down has failed, and, freed from its mooring it has flipped up and drifted out of place.

This is usually not a painful problem, but if the gland is getting traumatized or dried out it may swell or become ulcerated, which is irritating to the pet. More importantly, if the gland remains out for a matter of months it may become damaged enough that it no longer functions. You may not notice the effects of the loss of that gland function for many years, but as a dog ages his tear production reduces, and if he is already missing part of his tear production due to a longstanding cherry eye he very well may develop dry eye problems that lead to great discomfort, possible vision loss, and lots and lots of expensive medication to try to compensate for the lack of tears.

The oldtimer way to fix this problem was to anesthetize the dog, pick up the gland with some forceps, and snip it off. That technique does have the benefit of being quick and easy, and you never have to worry about the gland popping back up again. In a recent lecture, right after he finished saying that using that technique is actionable malpractice, the ophthamologist likened using that procedure to amputating someone’s little finger because it was broken. The problem would definitely be solved, but life would probably be better for the patient if a little extra effort was put into saving the function of the body part. The fact of the matter is that loss of function in that gland, whether through prolonged exposure or surgical removal will predictably result in problems for that eye later on in life.

The approved techniques for fixing cherry eyes involve either forming a pocket and tucking the gland back into place, or suturing the gland to deeper structures to keep it from flipping up again. Occasionally the gland will prolapse again after having been surgically fixed, so a second surgery to replace the gland must be performed. These are somewhat more complicated surgeries than amputating the gland, but they preserve the function of the gland for the future. By the way, because the tendency to develop a cherry eye is an anatomical trait, many dogs that get a cherry eye in one eye will also develop the same problem in the other eye.

Although any dog could develop cherry eye, several breeds of dog are particularly predisposed. A non-exhaustive list includes Cocker Spaniels, Shih Tzus, Lhasa Apsos, Boston Terriers, Pit Bulls, and Neopolitan Mastiffs. One cat breed, the Burmese, also has a tendency toward cherry eye due to the shortened shape of their faces.

I hope that all you new puppy owners out there will not have to deal with this problem, but now if you see it at least you will know what it is and what needs to be done.