For much of the year, soaking hay to protect the lungs of horses with recurrent airway obstruction (ROA, also known as heaves) is easy: You simply immerse the flakes in a large bucket of water for an hour before feeding, and dust is dramatically reduced. In winter, however, water may turn to ice before soaking is completed.
Don’t even think about using bucket heaters to warm up water that contains hay---that’s a fire hazard. Instead, try adding salt to the water to lower its freezing point. One cup of salt added to a large muck bucket will probably keep the water from freezing long enough for the hay to soak. The salt won’t harm your horse, and even if the hay freezes after you’ve given it to him, he will probably still happily eat it.
This article first appeared in EQUUS issue #449, February 2015.