I use frontline and have never had a problem. However, a friend of mine used it this summer (and had been using it) and had a HUGE flea problem! I think it will also depend on what type of environment you live in.
Lu has really bad allergies so we were instructed by the vet to use both revolution and advantage... Revolution has heart worm med and have pest treatment.
I tend to split them (not give her the same dose at once) and will sometimes skip a month if she is not showing symptoms. I hate using a lot of chemicals on her especially when a friend of ours told us that all of the pitts she has rescued have been very prone to cancer =0
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