I was also deciding between pre-vet and pre-med, and I didn't make a final decision until my junior year, so don't feel like you have to decide right away. Shadowing both vets and physicians helped me make my decision -- I realized that while I love animals, I didn't want them to be my patients. I like working with people, and I feel like medicine offers many more opportunities for specialization. The poor job market for vets also affected my decision, as well as the fact that to get into vet school you need a huge amount of hours working with animals (I love working with dogs, but I had no desire to shadow farm vets which is required by several vet schools if I recall correctly). Still, there were things I liked about being a vet, like the fact that a vet can serve as a primary care provider and surgeon for their patients at the same time. In the end, you need to make the decision based on what your priorities are and what you think will make you happiest.