Conditions Helped by Hay Soaking

Research shows that soaking hay before feeding can help a variety of equine health conditions.

Hay Soaking

Proper hay soaking can benefit several different, and sometimes related, equine health conditions. The process can reduce both allergens and nonstructural carbohydrates in forage.

Photo: Michelle N. Anderson, Digital Managing Editor

Hay Nutrition Testing

Having a laboratory test your hay for its nutritional content can help you and your veterinarian make decisions about how to best feed your horse and determine if hay soaking is necessary.

Photo: The Horse Staff

Cushing’s/Pituitary Pars Intermedia Dysfuction (PPID)

Experts recommend feeding PPID horses hay with less than 12% nonstructural carbohydrates (NSC), and preferably less than 10%. Hay soaking can reduce NSC in hay.

Photo: Dusty Perin

Recurrent Airway Obstruction (RAO)

RAO, also known as heaves, is exacerbated by exposure to dust and pollen. Wetting down hay before feeding can reduce your horse’s exposure to these irritants.

Photo: Anne M. Eberhardt/The Horse


Many horse health problems can lead to laminitis, a devastating hoof disease. Laminitis precursors include insulin resistance (IR), equine metabolic syndrome (EMS), and obesity.

Photo: Christy M. West

Insulin Resistance (IR) and Equine Metabolic Syndrome (EMS)

Horses are sensitive to even small increases in carbohydrate intake. One way to minimize laminitis development, particularly in horses with IR or EMS, is by soaking hay to reduce the NSC content.



Obesity results from overfeeding and a lack of physical exercise. Reducing nonstructural carbohydrates (NSC) in grass hay through soaking can help in managing obese horses' weight.

Photo: University of Kentucky's College of Agriculture, Food, and Environment

Polysaccharide Storage Myopathy (PSSM)

PSSM is a muscle disorder exacerbated by feeding high-NSC diets. Veterinarians and nutritionists currently recommend feeding horses with PSSM a diet containing less than 10% of daily digestible energy supplied by NSC.

Photo: Molly McCue, DVM,MS, PhD, Dipl. ACVIM

Hyperkalemic Periodic Paralysis (HYPP)

Soaking hay can decrease levels of certain minerals, such as potassium, in forage. Research suggests this practice could benefit horses with HYPP, a genetic condition that results in high levels of potassium, leading to muscle twitching or even paralysis.

Photo: Mathea Kelley