Desperate about fly and mosquito control

Hi farmers. I am new to Daves and so excited about this forum particularly! I have 1 acre, 2 dogs 3 cats, 3 horses, 7 new chicks and one baby turkey (!). West Nile will hit us hard this year and I want a sure fire wipe or spray (or other fly control). My mare has a fly allergy and gets ragged looking. I will cover her this year as garlic didn't work, nor do the pyrithrum based fly sprays. Does anyone have a remedy for dogs and other horses to keep off the mosquitos? I heard that pine tar can work...
Also, does anyone have experience with fly predators? Those little wasps?
I appreciate any suggestions. I would like to keep it organic too, a tall order I know.
Thanks in advance...