You should think very hard if you really want to do that many AS/A2 subjects.
For veterinary medicine, you only need 3 A2 levels and an AS, with usually a need for Biology and Chemistry. The extra subjects are obviously good but beyond 3 A2 is really unneccessary as far as veterinary applications go, it's much more important you get as good grades as you can in Biology and Chemistry; as well as pursuing work experience, etc.
Don't get me wrong it's not a bad thing to do, I personally did my Maths A level in one year as well as doing Bio/Chem/Phys, but it really isn't neccessary, and if it'll possibly cost your Biology and Chemistry results, then don't do it as it'll hurt your application.