Visiting Vet: Entropion

Why are my dog’s eyes watering?

Entropion is a condition in which part of the eyelid rolls inward. —Trevor Hurlbut/WikiCommons

“It’s about time,” I said with a smile when a former client returned with a new puppy. It had been years since his old dogs had passed away, and I was so glad to see him with a new friend. Baldur, an adorable chocolate Lab, passed his introductory physical exam with flying colors, except for one problem. His eyes were watering … a lot … tears running down both cheeks. Many things can cause “ocular discharge.” Blocked tear ducts. Allergies. Environmental irritants. But in Baldur’s case, I suspected a conformational problem called entropion. If only he would stop wiggling long enough for me to get a good look!

Entropion is a condition in which part of the eyelid rolls inward, causing eyelashes, skin, and/or fur to rub against the eye. Baldur’s body thinks “There’s something in my eye!” and Mother Nature turns on the tear faucets to rinse away the offending foreign material. Except the “foreign material” isn’t foreign at all. It’s Baldur’s own eyelid, and no amount of crying is gonna wash it away.

Entropion occurs most frequently in young, large-breed dogs. Breeds predisposed to the disorder include cocker spaniel, bloodhound, mastiff, Chesapeake Bay retriever, shar-pei, chow chow, Doberman pinscher, bulldog, golden retriever, great Dane, great Pyrenees, Irish setter, Labrador retriever, Newfoundland, Rottweiler, Saint Bernard, Boxer, Cavalier King Charles Spaniel, poodle, pug, and springer spaniel. In most cases, it is the outer portion of the lower lid that rolls inward, except in pug-faced breeds, in which entropion typically affects the lower lid, close to that smooshed-in nose.

Depending on severity of the roll, symptoms range from mild to severe. Mild cases may have minimal signs, like Balder’s watery eyes. Symptoms in more severe cases include inflammation, redness, squinting, and opaque yellow or green discharge. If the rolled lid rubs directly on the eyeball, it can cause corneal ulceration, erosions, and scarring. The cornea may turn cloudy or white, and little red blood vessels may grow across the surface as the body attempts to heal that ulcer … but the body can’t heal, because that darn rolled-in lid is constantly chafing that eye. Every time I tried to hold Baldur steady and look closely at his eyelid conformation, he would pull his head away and try to bite me. Not mean bites. Puppy bites. “What a fun game!” he was obviously thinking.

“Hold still, I want to make a diagnosis,” I thought in reply. But Baldur was having too much fun trying to subdue my hand. I changed tack. Releasing my hold on his face, I just grabbed my exam light and pointed it at him, seeing if better illumination would better illuminate his anatomy.

“Too bright, too bright!” Baldur reacted, squinting his eyes shut against the glare. So now I couldn’t tell anything about his eyelids. Finally, I turned off the bright light, let go of the oh-so-happy puppy, and just sat back and observed him. Baldur relaxed, stopped squirming, and looked up at me expectantly. Yup. Entropion.

Very mild cases may not require treatment. Some pups even outgrow entropion as their heads and faces reach adult size and shape. Most cases, however, need to be surgically corrected to avoid permanent damage to the eye, not to mention chronic discomfort for the dog. The basic surgical procedure involves removing a crescent-shaped bit of skin right below the rolled portion of lid, then suturing the incision to “unroll” the lid, everting it to the desired position. The trouble is that it is easy to over- or undercorrect, especially if you’re working on a dog who’s not fully grown. Thus, there are differing opinions about the optimum time to perform entropion surgery.

In puppies, it is usually better to delay cutting the lids until they are older. If the case is so severe that early intervention is needed to prevent permanent damage, temporary “tacking” sutures can be used to pull the eyelid edge away from the eyeball. This protects the eye while the pup matures, and may even help the eyelid grow into a better position. In people with entropion, this tacking procedure is done with local anesthetic, but squirmy puppies like Baldur need general anesthesia. I have heard some veterinarians tack the lids using surgical staples, without anesthesia. Not me, thanks! If Baldur won’t hold still for an exam, he’s not gonna hold still being stapled. Besides … ouch!

Temporary tacking sutures or staples need to be replaced periodically as the puppy grows, but once he’s close to adult size, permanent corrective surgery can be done. Back in the old days of veterinary medicine, “Old Doc” would routinely do this surgery in private practice. After all, it’s basically just a nip and tuck. Except when it’s not. Sometimes it’s much more complicated. If the corner of the eye rolls in, fancier surgical techniques are needed for effective repair. If the eyelids are excessively long, as is common with breeds with lots of facial skin folds, like shar-pei, there are eyelid-shortening techniques. If the dog also has excessively droopy lids (think bloodhound), other concurrent corrective procedures may be indicated. So, nowadays, your local veterinarian is as likely to refer you to a veterinary ophthalmologist for surgery as to do it herself.

Baldur’s lower lids were not touching his actual eyeball, and despite the tearing, he did not seem uncomfortable. If symptoms persist, we’ll discuss temporary tacking, but I’d prefer to wait until he is older. He needs to be able to tolerate an Elizabethan collar (the cone on the head contraption), and I don’t want to risk his rubbing at tacking sutures and making things worse instead of better. We may send him off to the ophthalmologist eventually. For now, I’m waiting until he returns for his next puppy visit, when I will give him something to chew on (besides my hand) and try to persuade him to sit still long enough for me to gaze into those big brown eyes and reassess the situation.