Boy am I dense!I see those everyday on the cattle in the back pasture.I never thought of that!Would i use the permethrin-based kind?

Hello all.I'm new to this site and I hope I'm doin this right.Anyway,I live in south Louisiana and we have a REALLY bad problem with biting flies.Sometimes the tips of my dogs ears will scab over because of the scratching.Any suggestions on a product that I don't have to apply every 2-3 days and dosen't cost an arm and a leg?And how do about mosquito controll?Any help would be great.