I've been using garlic, seasonally
, since Spring 2004 but I use it for tick control. I will start feeding garlic in mid-March and keep three of my four on it until November - when the ticks stop being so active around here.
Looking back, I don't seem to have the fly problems I would expect because we are surrounded by beef cattle. But I can also count on one hand the mosquitoes I see every year. If the OP wants to try garlic, there are two no-no's:
1. Do not feed raw garlic.
If a horse is going to become anemic from eating garlic, it's because of the allicin (sp?) in raw garlic. It's processed out of powdered garlic.
2. If your horse colics easy or has ulcer issues, I wouldn't feed garlic.
Garlic caused my Arab's ulcers to flare the first summer I put everyone on it, so he gets spray once or twice a week with Repel-X.
I have been buying from www.herbs4horses.com
in Memphis, TN since 2004. They are honest and generally ship the same day you call, if you call early enough in the day
I buy a lot more than garlic from this company and have never had anything to complain about
Also, diet plays a large role in fly attraction. Feeding sweet feed or anything that one of the first three ingredients is molasses, is a fly magnet.
My friend's husband can smell a horse that eats sweet feed, when they're sweated up on the trails. They have asked the riders, just to be sure, and his sniffer is 100% on the money to-date.
If a sensitive human nose can smell that stuff, think how it attracts the flies