Hattie B, Magical Vet: The Pony's Hoof (Book 5), Paperback/Claire Taylor-Smith

Evil King Ivar of the Imps has hurt the little pony's hoof and stolen his magical powers. Hattie just needs one apple and some special spice to help him, but it's going to be harder than she thinks to get it - King Ivar is waiting for her...