Peripartum mares and neonatal foals are physiologically unstable. Although hormonal changes around the parturition have been well studied in the field of endocrinology, hematological and biochemical changes have been studied little. The purpose of this study was to examine hematological and biochemical changes in peripartum mares and neonatal foals (n = 23; heavy draft horse).  This study revealed hematological and biochemical dynamics in peripartum mares and neonatal foals.