Kinda depends on where you are. Mosquitoes and standing water are theoretical concepts out here. I haven't seen a mosquito in years??
There are homeopathic prevention I "think " food grade diatomaceous earth is one? But if your in a high risk area I think you need to be pretty aggressive in Mosquito season.
Heartworms | Truth4Dogs
I think I found my vet. What do you guys think?
Two other links in there with more info and be sure and look at the Trifexis warning!