By Dr. Becker
Entropion is a condition in which a portion of a dog’s or cat’s eyelid is inverted, meaning it’s folded or rolled inward. This can cause eyelashes or other hair to rub against the surface of your pet’s eye, causing irritation and pain. And if the rubbing causes scratches on the surface of the eye, it can lead to corneal ulceration or perforation. It can also cause scar tissue to grow over the injury in a condition known as pigmentary keratitis.
Entropion can occur in either the upper or lower eyelid, and in one eye or both. If left untreated, it can cause a decrease in vision or complete loss of eyesight.
Causes of Entropion and Pets Most at Risk
Entropion is relatively common in dogs. When it’s an inherited condition, it usually occurs before the dog turns a year old. Many breeds are predisposed to the disorder, including the Boxer, Bull Mastiff, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chow, Cocker Spaniel, English Bulldog, Golden Retriever, Great Dane, Irish Setter, Labrador Retriever, Poodle, Pug, Shar-Pei, Springer Spaniel, and the Saint Bernard.
Selective breeding for specific physical traits such as a certain head shape, skin folds on the face, or prominent eyes can contribute to a genetic predisposition to entropion. In brachycephalic breeds (dogs and cats with pushed-in faces), there is more tension on the ligaments of the inner eye than normal. This tension, coupled with the shape of the nose and face, can result in both upper and lower lids rolling inward.
In giant breed dogs, the opposite problem can exist. They can actually have too much slack in the ligaments around the outer corners of the eyes, which allows the outer edges of the eyelids to fold inward.
In cats, it’s typically the brachy breeds like Persians that are at risk. The condition is usually diagnosed around the time the cat reaches his second birthday.
Entropion can also occur as a secondary condition as the result of eyelid scarring, an eye infection like conjunctivitis that causes spastic entropion, corneal spasms, trauma, and nerve damage.
Inflammation of the muscles used for chewing, and also significant weight loss, can lead to loss of fat and muscle around the eye socket. This changes facial structure, which can cause entropion as a secondary condition.
Common Symptoms of Entropion
A pet with entropion will typically squint and have an excessive amount of discharge from the affected eye. Some pets produce a mucus-like discharge. Sometimes there can be sensitivity to light and pawing at the eyes, especially when the animal is outside.
Other signs of entropion include inner eye inflammation (which is called keratitis), an eye tic, a sagging of the skin around the eye socket, or in worst-case scenarios, a rupture of the cornea.
Brachycephalic breeds with entropion involving the inner corner of the eye may not show any symptoms of discomfort simply because of their facial construction.
Some cases of entropion are never more than a minor annoyance, while more severe cases can cause significant pain, eye ulceration, scarring, and ultimately, loss of vision.
Diagnosis and Treatment
Entropion can be diagnosed through an ocular exam performed by your veterinarian. Typically, a local anesthetic eye drop is used to make the exam more comfortable for the patient. To check for corneal ulcers, a fluorescein dye may also be used.
In very mild cases of entropion, vets often prescribe lubricating eye drops or eye gels to help the eyelids glide less abrasively over the cornea. Sometimes antibiotic ointments are also prescribed to control potential damage or infection to the cornea. However, topical eye ointments can’t resolve the underlying condition of the eyelid actually rolling or folding over.
Eyelid surgery is the only treatment that will permanently fix this condition. If the entropion is causing corneal damage, I recommend surgery to improve the pet’s quality of life and long-term eye health.
Puppies under six months of age typically have a minor procedure called lid tacking instead of the more in-depth procedure called blepharoplasty, where the eyelids are actually surgically reshaped. Lid tacking is the placement of temporary sutures that roll the eyelids out and keep the eyes healthy until the patient grows into his permanent adult facial features.
In pets with corneal ulcers caused by entropion, the ulcers will need to be treated as well, typically with a medicated eye ointment that promotes healing.
Animals with inherited entropion should not be bred.
The prognosis for pets with entropion is excellent, provided treatment is given before there is damage to the cornea. If the cornea is damaged, the prognosis will depend on the type and severity of the damage.