Juui Dolittle

Kenichi Tottori is a highly competent vet that has been nicknamed "Dolittle." He's very strict with pet owners and the money they owe him, but he really is a great vet. Often, he ends up not only helping the pet, but also the owner. The manga starts off when a young woman, Asuka Tajima, asks him to treat a racehorse, Asuka Mirai, who has a broken leg. She accepts the high cost of treating the horse, but is shocked by the level of suffering the horse will have to endure to in order to heal.

(Source: MangaHelpers)