Death from ketosis rarely occurs. Cows that develop ketosis are usually in negative energy balance and, therefore, are mobilizing body stores of fat and protein because of a drop in blood sugar or glucose levels. When fat molecules reach the liver, they are converted to ketones, which results in elevated ketone levels in the blood. As the blood ketone level increases, the cow progresses into subclinical ketosis. The second major change in the blood accompanying elevated ketones is a decrease in blood glucose.
Tests are available to check the ketone levels of milk and urine.
The ketone level of milk is about half the blood level, where as the ketone level of urine exceeds the level in blood by about four times. This makes the urine test for ketone levels overly sensitive for diagnoses, with most high-producing cows showing positive urine tests in early lactation, often without need for treatment. The milk test is considered more accurate for indicating when there may be a problem. The primary aim of all treatments is to increase blood glucose and glucose supply to tissues, thus decreasing body fat mobilization. The treatment of choice is an intravenous infusion of glucose, which is the most rapid and direct way to supply sugar.