An evaluation of milk ketone tests for the prediction of left displaced abomasum in dairy cows.

Two commercial milk ketone tests (Ketocheck) Great States, St. Joseph, MI and Ketolac BHB; Hoechst, Unterschleissheim, Germany) were used with milk samples collected within 2 wk postpartum to evaluate the use of these tests in the prediction of left displaced abomasum in dairy cows. Odds ratios, sensitivities, specificities, and likelihood ratios were determined. For the study of Ketocheck, 47 milk samples from 26 cows that were later diagnosed with left displaced abomasum were taken at a median of 6 d postpartum (12 d prior to diagnosis of the disease. For the study of Ketolac BHB, 26 milk samples from 15 cows that were later diagnosed with left displaced abomasum were taken at a median of 6 d postpartum (11 d prior to diagnosis of the disease). Each cow that was subsequently diagnosed with left displaced abomasum was matched with three control cows by herd and calving date. Positive Ketocheck results and Ketolac BHB results that indicated > or = 100 or > or = 200 mumol of beta-hydroxybutyrate (BHBA)/L of milk were significantly associated with the subsequent diagnosis of left displaced abomasum. The sensitivity of Ketocheck for the prediction of left displaced abomasum was 22%; specificity was 96%. The sensitivity of Ketolac BHB for the prediction of left displaced abomasum was 46% when the results indicated > or = 100 mumol of BHBA/L and was 34% when the results indicated > or = 200 mumol of BHBA/L. Ketocheck and Ketolac BHB might be used as tests for the prediction of left displaced abomasum when used with milk sampled within 2 wk postpartum. Hyperketolactia is a significant risk factor of left displaced abomasum.