[QUOTE=LauraKY;6783928]
A friend of mine with a headshaker finally called in an equine allergist. She started him on allergy shots and the headshaking is gone.[/QUOTE]
I was going to suggest looking into this, as well. I’m not a headshaking expert, but I’ve dealt with plenty of allergies (generally mine). Allergies can be managed - even potentially cured - with shots. It’s immunotherapy, so there’s no medication to cause side effects or make your horse nutty.
I’ve received shots for years and THEY WORK. I also gave my gelding shots for awhile and they really helped him in a short period of time. (Unlike decongestants which made him so hyper he was absolutely unrideable!)
Wetting the hay helps with allergies, as well.