With the chronic form of the disease, horses often appear clinically normal, but may have very slight to moderate decreases in athletic performance. To diagnose a horse with this condition, a veterinarian will want to rule out hypothyroidism, laminitis, pleuritis, and colic. Elevated levels of these muscle enzymes indicate significant muscle damage. But if the cramping is severe, muscle degeneration can result in myoglobin or muscle protein release into the urine. Myoglobin is toxic to the kidney and can cause acute renal failure and death.
Many factors seem to contribute to recurrent problems, and several treatments show promise.
Decreasing the quantity of grain fed and feeding greater quantities of high-quality hay can be beneficial. Regular, not intermittent, exercise is also important. Feeding balanced electrolytes such as potassium, calcium, sodium, and magnesium may improve muscle function. B-complex vitamins, vitamin E, and selenium are effective supplements in some horses. Besides diet changes and supplementation, rest is typically recommended until the horse's muscle enzymes return to normal.