glucose levels alone are insufficient to diagnose ems. many ems horses will effectively compensate their insulin response even with insulin resistance, maintaining a blood glucose within normal limits, although usually at the high end of normal. other factors, such as stress, feeding, inflammation, or administration of α-2 agonist drugs such as xylazine and detomidine, can falsely raise blood glucose levels. horses with persistent hyperglycemia may have type ii diabetes.