How do I study VetMed in the US?

I am a Malaysian studying at a British international school doing A-Levels. I've done my research and it is still ongoing. However, I am still unsure of whether A-levels is accepted as a pre-U in the US. Admission tutors aren't much help either...they direct me back to their Uni websites which don't answe my questions! Help, anyone? What is the actual process, do I study for a degree before my vet med course? Confused.