allergy prevention

Two of my four horses are struggling with all this dry weather and the consequent higher exposure to allergens. This results in them wheezing. I have guidance from my vet and have treatment options if it gets worse etc but wondered if anyone had any further tips to manage and prevent it...

I’ve been trawling the forums but can only find info about horses with allergies. My boyfriend is getting into horses and despite the vicks around the nose, long sleeves and gloves and antihistamines he still is having crazy allergic reactions! He’s allergic to pretty much all animals but...