My vet won't let me use the Frontline Plus on Abbey. She is 5 months old and 2.8 lbs. She put Abbey on Revolution. I'm not sure if I like it though. Abbey has had 2 ticks on her this spring. They have only been on her hair not her skin. I'm not sure if Frontline would completely keep them off or not. Hopefully when she gets bigger I'll try the Frontline Plus.