The Adventures of Black Beauty S01E01 - The Fugitive

A spirited black horse escapes from a dealer and is found ailing by Vicky Gordon, who quickly falls in love with him. Vicky's father, the new doctor in town, treats the horse's illness and refuses to surrender him until he's well. The owner agrees to let the horse stay a few days before he takes him to be sold. When the owner falls ill the doctor hurries on horseback to save his life. Soon after, the man gives the horse to the doctor.