[theBCnut]

There are natural alternatives, but they require giving them 3 times a day. I give the monthly every 45 days and if you live where it actually freezes, you can stop giving it over the winter. I try to give Ivermectin and not give the ones with extra wormers, flea treatments, etc. I save those for when the big guns are really needed. For a week after you give heartworm prevention, you can give milk thistle to help the liver detox.