What often characterizes hereditary entropion?

Hereditary entropion is primarily characterized by excessive facial folds, particularly in certain breeds where this condition is commonly seen. In these breeds, the genetic predisposition results in an abnormality of eyelid anatomy, which can lead to inward rolling of the eyelids. This excessive folding can cause the eyelashes and eyelid margin to rub against the cornea, leading to irritation and potential serious complications such as corneal ulceration.

The focus on hereditary factors and the structural issues that arise from excessive facial folds is crucial in understanding why this is the defining characteristic of hereditary entropion. This condition is distinct from age-related skin changes or environmental factors, which may influence other types of entropion but are not the core issues associated with hereditary forms. Similarly, previous eye injuries typically pertain to acquired entropion rather than hereditary conditions, reinforcing that the anatomical predisposition is central to hereditary entropion.