Bovine Ketosis

Ketosis is characterized by abnormally high concentrations of ketones in the blood as a result of a negative energy balance, in which dietary carbohydrate intake is inadequate to meet energy needs, resulting in a decline in blood glucose concentration and subsequent mobilization of LCFAs from body fat stores. A proportion of LCFAs are metabolized in the liver to form ketone bodies: acetone, acetoacetate, and β-hydroxybutyrate (BHBA). Ketones are used by muscle as an alternate energy source.

Bovine ketosis is often seen in high producing dairy cows in early lactation (milk production places extreme energy demands on the body). Development of ketosis is related to both increased body condition and inadequate nutritional management in the peri-partum period. Clinical signs include depression, gradual inappetence, decreased milk production, weight loss and occasionally nervous signs. Affected cows have hyperketonemia and hypoglycemia and may develop hepatic lipidosis. Cows with ketosis in early lactation have a higher incidence of diseases such as displaced abomasum, metritis, and mastitis.

Ketones are most often measured cow-side in milk or urine using commercially available kits that detect acetone or acetoacetate. Milk tests are more specific than urine tests and positive results usually indicate clinical ketosis. BHBA measurement in milk is more sensitive than measurement of acetone or acetoacetate in milk. BHBA in serum is the current “gold standard” for the diagnosis of ketosis but a special handheld instrument is required.