[kogeki]

just wondering
what is the difference between the stuff you would get from a vet and stuff in the stores?

I don't see a difference between what you get from the vet and what you get from the store. Frontline from a store is the same product that you get from a vet. You just have to make sure you get the correct weight class. Now, if you are talking about just the crappy brands they sell in the store, thats a different story.