What term describes something that is of, or relating to horses?

The term "equine" specifically pertains to horses and anything related to them. This term is derived from the Latin word "equus," which means horse. In veterinary science and related fields, understanding terminology that relates to different animal classes is crucial. Equine refers broadly to horses, ponies, donkeys, and zebras, encompassing aspects of their care, breeding, and medical treatment.

On the other hand, the other terms refer to different groups of animals: "galline" relates to chickens and birds, "bovine" pertains to cattle such as cows and bulls, and "ovine" refers to sheep. These distinctions are important, especially in veterinary contexts, where specific terminology is used to address the needs and characteristics of different species. Thus, within the context of discussing horses, "equine" is the correct choice.