A vet clinic is allowing me to shadow for a day to start off. She never really told me the appropriate attire to wear. Would a white v-neck t-shirt and jeans be okay?
You should call and ask. Generally you either need to wear something nicer, like khakis and a nice blouse, or they will have you wear scrubs. Unless they tell you that you can wear jeans, I would go for something nicer and more professional. Hope this helps!
Something comfortable since you'll probably be on your feet the entire time. I would die without my danskos but (clean) sneakers would probably work too.
Close-toed, comfortable, and ideally something that sheds bodily fluids easily or cleans easily. You just never know.
And the others are right: you should call and ask what to wear. It's an all-around win: it signals to them that you care about their image, and you automatically know you're showing up in the right clothes (so no stress for you).
Is it small animal? Before I got a pair of scrubs I wore a pair of dress pants and dark blue button ups every day to work. I figured that you can't look too professional... unless you're wearing a suit which I wasn't going to do.