I live in Coastal Texas where it's also hot and humid much of the year, and our vet has withdrawn his support for Revolution. When it first came out, he recommended it, along with Sentinel, but over the years found out that these combo pills just don't have enough heartworm and flea/tick protection for our area. Animals on Revolution and Sentinel were getting heartworm and flea/tick infestations. Our flea/tick problem here is awful because we never get enough cold weather to kill the pests.
I use K-9 Advantix on my other dogs with no ill effects but I'm using BioSpot on Bobby. He's so much smaller than my other dogs and BioSpot doesn't seem as strong as the others. It seems to be working fine.
Julie |