"Pre-Veterinary Medicine is for those students who have an eye on veterinary school. Veterinarians are skilled at caring for animals—diagnosing and treating their health problems, preventing those problems from happening—basically ensuring these critters' well-being. Vets often choose between working with small animals and working with larger ones (such as farm animals), but there are plenty of vets who are capable of working with all sizes.
Pre-Veterinary Medicine programs at most colleges encompass science and math courses that most veterinary schools require for admittance. Biology, chemistry, organic chemistry, and other courses will form a large part of your curriculum, as well as classes in animal sciences and zoology. Getting involved in an internship or volunteering in a vet’s office are both great ways to augment your studies and get a little experience before veterinary school.
Most veterinary schools don’t require you to major in Pre-Veterinary Medicine. The most important things schools look for is a strong background in science and math—and, if possible, actual veterinary observation or experience." (Princeton Reviews)