I have found that you can save a lot of money ordering through the mail. Heartworm medication and some of the others have to have a prescription accompanying them, but you can get your Frontline and other things without a prescription. I found one recently called www.EntirelyPets.com and the heartworm medication was about half the price of what I had just paid at the vet's office. I have also ordered from www.healthypets.com .