My major is veterinary medicine. It's an undergraduate course in the UK. Also, we're at Oxbridge, so it's a six day week and very intensive periods of study (short terms instead of semesters).
Personally, I didn't have my horse here the first two years, and it meant I got to try new things, meet people and generally have the time to fully experience being at uni. But I found that I really missed horses, ended up getting the horse I have now last year, and rode him at home. Next year I'm brining him down, but by then I will be a fourth year, and into the clinical part of my course when a lot of my friends doing other subjects will have graduated, so I feel that the emphasis will move from going out, and I will be able to enjoy having my horse here without worrying about missing out. I'm also settled, know the area and the horse people/scene from riding other people's horses here, so I'm prepared for it.
This isn't to say that it's not doable and enjoyable, but it will change your experience and is worth thinking over. I would always recommend going and seeing what uni is like before committing to a horse: I know two other friends who have done the same as me, and left the horse at home first, and it has worked out so much better for them that way.