Our pups (two four month old labs) just had a nasty reaction (persistent diarrhea) to Heartgard Plus so I've been researching others. Vet gave us Revolution for next month, but it looks like it still has some nasty adverse effects. https://www.dogsnaturallymagazine.com/risks-of-heartworm-drugs/. My research shows diarrhea as a side effect for Revolution too. Has anyone experienced diarrhea with Heartgard Plus but had success with Revolution? Thank you in advance!