Well, I wasn't pre-vet in undergrad, but one of my favorite things I did was volunteer in wildlife rehab. It's not something I would choose to do as a career, but it was amazing to see a variety of different species (snakes, turtles, songbirds, birds of prey, squirrels, rabbits, possums, etc.) and the emergency medicine aspects of it as well. It's also amazing to know you can do so much for so many animals with so few supplies.
Also, if your college has it, I'd recommend taking a food animal care class. Again, not what I want to do as a career, but it was great to feel comfortable with cattle, sheep, goats, and pigs. In fact, I'm doing Food Animal Medicine and Surgery next semester as my clinical exposure.