The study was conducted on 79 high performance dairy cows of the race Holstein Friesian that showed ketosis in Hanoi vicinity. The main findings were: - The affected cows usually showed the digestive troubles; emancipation and low milk productivity; the ketones were found in the body fluids (blood, urine and milk) in 100 percent of the cows. - The red blood cell number, the hematocrit, the hemoglobin values, the white blood cell number in the affected cows were decreased, lower than those of the normal cows. - The alkaline reserve and the sugar in the blood decreased and the ketones were found increased as high as the double the amount found in the normal cows. - Two treatment protocols were tested and resulted as effective. However, the protocol number two was more effective than the number one.