Cortisol in pregnancy toxaemia of sheep

Of 31 pregnant ewes with clinical signs of pregnancy toxaemia, 24 had hypoglycaemia and hyperketonaemia at the time that a single blood sample was obtained. Twenty-five of these had a plasma cortisol concentration in excess of 10 ng/ml and six had a value below this. All the seven animals which did not show both hypoglycaemia and hyperketonaemia had a plasma cortisol concentration in excess of 10 ng/ml. Taking all the sheep together, 80% had a high plasma cortisol concentration. This could be the consequence of increased adrenal output or reduced excretion by the liver.