I would consider pursuing an undergraduate degree in Animal Sciences or General Biology if the school you're applying to does not offer a Pre-Veterinary degree. Studying either of these subjects will provide a relevant introduction to the field of Veterinary Medicine.
Maxwell recommends the following next steps:
I’d recommend looking at which vet schools you are interested in applying and determine what their requirements are. That way you can decide which coursework better allows you to complete the prerequisites and ultimately achieve your major degree. Regardless if you are interested in small or large animal specialty (or other species), having a science background in undergraduate studies is very helpful. For large animals specialty, having agricultural coursework is also very helpful.