Experimental studies were carried out on the basis of a breeding enterprise in the Sverdlovsk region. The assessment of the extent of ketosis distribution was carried out on the basis of data from a clinical examination of 1246 cows of the new calving period. It has been established that 10,9% of cows show clinical signs of ketosis. Additionally, an extended biochemical blood test was performed in 114 cows with ketosis. The group of examined animals included cows of the new calving period of the Holstein breed of 1-3 lactations, with a milk production of more than 7000 kg per lactation. The diagnosis was established by testing with glucometer (WellionVet Belua). In cows with ketosis, metabolic signs of impaired protein, lipid and carbohydrate metabolism, stressed functioning of buffer systems were established. A decrease in the content of total protein and the amount of albumin by 4,5–27,0%, and cholesterol by 12,3–57,3% relative to the normative physiological values was determined. Signs of hypoglycemia are recorded in 50,0% of cows with clinical signs of ketosis. A decrease in the level of bicarbonates was found to be less than 15,9 mmol/l in 25,0% of cows. In most cows, a tendency to increase the activity of enzymes was recorded. The activity of aspartate aminotransferase in the group was 103,05±13,40 U/l, creatine phosphate kinase – 440,05±418,50 U/l and lactate dehydrogenase – 989,07±196,48 U/l.