All Natural Herbs for Mares With Hard Heat Cycles Every professional rider and equine veterinarian has dealt with a mean mare in heat, usually due to a long heat cycle. If you’re searching for all natural ways to calm your mare, look no further! Our herbal supplements are specially-designed to naturally calm mares and assist their owners in managing their heat cycles. Combined with exercise and proper diet, our herbs will work wonders against even the toughest of hard heat cycles, and in an all-natural way. SLH is a brand trusted by horse lovers for overall well-being, including handling mare hard heat cycles.