Keratinolytic disease of the zona alba (KDZA), commonly known as white line disease, is a hoof pathology present across a wide range of breeds and disciplines. Referred to previously as hollow wall or seedy toe — as well as by various other descriptors — KDZA emerged as the most clinically correct term for the pathology when it was introduced in 2018 by fourth-generation farrier and author Simon Curtis, PhD, FWCF (Hons), HonAssocRVCS, of Newmarket, England.

Heel pain is a common problem in performance horses. While treating it often requires trial and error, ingenuity and a good foundational trim lead to a positive prognosis for many horses.