Horses are often fed diets that also contain high levels of grains and supplements to maximise growth or productivity. Katie Young, PhD, consulting equine nutritionist for Purina Mills, presented information on forage options for horses with commonly encountered special needs, including recurrent airway obstruction (RAO) or chronic laminitis, at the Purina Equine Veterinary Conference.

Horses with RAO (also known as heaves) have a hypersensitivity to airborne allergens from hay, feed, or bedding, or pollens in summer pasture. Young recommended immersing hay in water so it is completely wet before feeding it to RAO horses. This quick dunk is as efficient in diminishing dust and mold as soaking would be, but it does not leach out nutrients. Avoid feeding from hay bunks or round bales that encourage horses to burrow their heads into hay and, thus, repeatedly expose them to the allergens.

Straight grains, such as rolled oats, can be twice as dusty as hay and might also need wetting. Owners can replace hay and grains with pelleted complete feeds to significantly decrease particulates from the diet that the horse could breathe in.

Young stressed that management strategies are critical for success with RAO horses–house these horses outside, or at least ensure excellent barn ventilation so the horse has an adequate supply of fresh air. Anything that increases dust concentration in shared airspace is problematic, so remove horses from the barn when mucking, stripping, or bedding a stall, or when distributing hay, even in adjacent stalls. For a horse with summer pasture-associated obstructive pulmonary disease, keep pasture short or keep the horse off pasture until winter