To eliminate mold commonly found in hay bales, West Chester, Pa., equine veterinarian Frank Reilly suggests “flash soaking” — tearing pieces of hay off of the bale, putting them in a hay net and then under a heavy rock in a bucket of water for 10 minutes. Studies have shown this reduces the organic dust count, he says.

It is not enough to just spray the hay with a hose or dunk it quickly in a tank instead of soaking it, he warns. As an added benefit, he notes, “Flash soaking can be helpful for older horses that can’t chew as well because their teeth are starting to go.”

He says the hay should not soak overnight, an outdated practice once thought to help horses with insulin resistance by decreasing the amount of sugar in the feed. Several studies have shown that overnight soaking increases the bacteria count in hay. “That’s not what we want,” he says. “We’ve got this syrupy mucus in the horse’s throat and we don’t want to add more bacteria right in front of his face so he’s inhaling it.”

Commercial hay steamers can also effectively reduce harmful bacteria, Reilly says, and can be especially useful in locations where cold temperatures could make flash-soaked hay too icy for feed. However, a commercially available steamer can cost $2,000, a prohibitive price for many. “On our website you can see how a gentleman took a drywall steamer from Home Depot and he hooked it up to a hose and a Rubbermaid container with a couple of holes to create his own steamer for $100. You can make your own steamer pretty easily, actually.”

For more insight on insulin resistance, read the American Farriers Journal special report “Insulin Resistance: Insights in Prevention and Treatment,” which is available with the December 2019 issue.