Which of the following is categorized as a blemish?

A blemish refers to a superficial or minor defect that does not necessarily affect the horse's performance but may impact its appearance or market value. A quarter crack is a specific type of blemish, typically occurring in the hoof wall, and involves a vertical crack that can appear near the quarters of the hoof. While it may cause some changes in the horse's gait or soundness issues if severe, it is generally considered a cosmetic issue rather than a serious injury.

On the other hand, conditions like founder, bowed tendon, and Wobbler Syndrome are more severe and involve structural or functional issues that can significantly impair the horse's performance and overall health, categorizing them as serious injuries rather than mere blemishes. Therefore, the identification of the quarter crack as a blemish highlights the distinction between superficial defects and more serious conditions associated with a horse's health and athletics.