Alphamale is probably correct but, since the required qualification is usually referred to simply as 'Biology', I'd feel that you'd be on safer ground if you studied 'normal' biology.
The really important subject to take is Chemistry. (You need a grade A pass). You also have to take 2 subjects from Biology, Physic and Maths so, theoretically, you don't have to take Biology at all (although I certainly wouldn't recommend not doing so).
Getting a place to train for vetinary surgery is the hardest of all career options (even harder than getting a place at medical school). The theoretical minimum entry level is 3 As and 2 Bs in your Highers but even 5 As won't automatically guarantee you a place. So there's a lot of hard work ahead of you - Good luck!
http://www.learndirect-advice.co.uk/helpwithyourcareer/j obprofiles/profiles/profile436/
Chris