Causes of Entropion
Entropion can be developmental/congenital (called primary entropion) or acquired (called secondary entropion). It is common in dogs and usually is apparent before one year of age - especially if it is congenital. Developmental entropion has a strong genetic component and is frequently caused by a hereditary abnormality in facial conformation and eyelid support. It is much more common in certain breeds whose faces are flat and whose noses are short. Breeds with pronounced heavy facial skin folds are also predisposed to entropion. The actual genetic basis of entropion is not well understood.
While most cases of entropion are developmental due to a hereditary predisposition tied to facial conformation and muscular and ligamentous eyelid support, entropion can also be acquired by dogs of any breed. Acquired entropion can be caused by eyelid spasms (called blepharospasm), loss of tone of the orbicularis oculi muscle, eyelid trauma, chronic inflammation, infection, obesity, marked weight loss or muscle and skin laxity associated with aging. Acquired entropion can be seen at any age but tends to be more common in older dogs.
Entropion is not “preventable,” per se. It typically is a conformational defect that must be corrected surgically.
The symptoms of entropion occasionally can be relieved by topical lubricating eye medications. However, the only way to “cure” the condition is through surgery. The prognosis for dogs with entropion is excellent as long as they are treated in a timely manner. Without surgical treatment, entropion can cause permanent corneal damage and, eventually, blindness. Dogs that have had corrective eyelid surgery cannot be shown in conformation classes under the rules of the American Kennel Club.