Called my vet to book my dog (90 lb male lab)in to get heart guard and Advantix I was told he needs to have a test done to make sure he doesn't already have heart worm so the test plus the heart guard plus a summers supply of Advantix they told me is 360$ Seems like a lot just wondering what others have payed as well as opinions on the 2 products and if I should be considering and alternative to either one?