Our breeder gave us one applicaiton of Frontline that I applied. It is coming time for another application and I think I have some choices to make. I asked the vet if we should continue, and he said "if you want to". I wasn't given a prescription for anything and was told I can buy it OTC. At that point, I considered switching from Frontline to K9 Advantix, but haven't purchased yet. Now I'm thinking about Heartworm/Parasite prevention - he didn't say anything about it. Is it advised to get one of the "all-in-one" type topical monthly treatments that would cover everything? What do you use?