title: Evaluation of liver function tests in neonatal calves.
abstract: OBJECTIVE
  To evaluate the efficacy of tests for hepatic disease in young calves.
  
  
  METHODS
  Prospective case-control study.
  
  
  METHODS
  28 clinically normal calves and 47 calves with histologically proven hepatic disease.
  
  
  METHODS
  Liver function tests and serum activity of liver-derived enzymes were determined on 28 clinically normal calves at birth and at 2 weeks of age. These values were compared with the results from 47 calves with hepatic disease verified by histologic examination. Upper limit of confidence interval was determined for the results on the clinically normal calves, and Student's t-test was used to identify significant differences in the data from calves of various age-groups.
  
  
  RESULTS
  None of the results of the common tests for liver damage or function (measurement of bilirubin, gamma-glutamyltransferase, glutamate dehydrogenase [GMD], alkaline phosphatase, L-lactate dehydrogenase, aspartate transaminase, or alanine transaminase) were clinically useful when used alone for detection of hepatic disease in calves less than 6 weeks old. Sensitivity of gamma-glutamyltransferase, GMD, aspartate transaminase, and alkaline phosphatase as indicators of hepatic disease in this population of calves was 0, 59, 80, and 9%, respectively. Direct bilirubin (sensitivity, 87%) was more sensitive than total bilirubin (sensitivity, 66%). Serum enzyme activity of most enzymes (P < 0.01), total bilirubin concentration (P < 0.001), and sulfobromophthalein sodium clearance half-life were significantly higher (P < 0.001) in newborn calves than in 2-week-old calves.
  
  
  CONCLUSIONS
  Clinical findings that indicate hepatic disease in calves that are less than 6 weeks old could be confirmed by measurement of serum activity of GMD or concentrations of total serum bile acids or direct bilirubin. Percutaneous liver biopsy may still be needed and may provide the most information.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D016022:Case-Control Studies; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000503:physiopathology; D005069:Evaluation Studies as Topic; D005260:Female; D008107:Liver Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary*; D008111:Liver Function Tests / Q000662:veterinary*; D008297:Male; D011446:Prospective Studies; D011897:Random Allocation