Our pharmacology was VERY difficult. Almost the whole class--every year--failed the midterm exam, and it was expected. It was confusing and poorly taught, and I was always frustrated because it seemed to important. I actually understood pharmacology much better once we started studying medicine, because then all the drugs were tied to diseases and pathology and I could use my brain to figure things out rather than memorising facts. If you have opportunities to shadow or do rotations, pay attention to the drugs that are used in various situations. This was one of my biggest stumbling points my first month, even with As in medicine and pharmacology! I had no clue how to turn that into real clife practical knowledge. So don't despair, as the academic setting isn't a good reflection of the real world. And heck, maybe getting the chance to go through everything a second time will solidify it in your head better than your classmates. You'll be paying close attention this time around, so maybe that will give you a really strong foundation for medicine class (& practice).
Like the others have said, come up with a plan for studying. Study more, or maybe more importantly, study in different ways. Use memory aids. Try the internet for resources made by other vet students. Learn the quirks of your professor (for our prof, knowing his weird biases toward/against certain drugs was half the battle). And remember it doesn't make you less of a (future) vet or ruin vet school! Once you get through it, you're through it, and in a few years whether you failed it the first time won't matter.
