Serum bile acids concentrations in healthy and clinically ill neonatal foals.
BACKGROUND
Reference ranges for serum bile acids (SBA) concentration are well established in healthy adult horses. Increased values are indicative of hepatic disease.


OBJECTIVE
SBA concentrations are significantly greater in the neonatal period compared with mature horses, and illness in the neonatal period will further increase SBA.


METHODS
Ten healthy mature horses, 12 healthy foals, and 31 clinically ill foals.


METHODS
Prospective cross-sectional study. Blood samples were obtained once from the mature horses, from healthy foals immediately after birth, at 2 days, and at 1, 2, 3, 4, and 6 weeks of age; and from ill foals less than 1 month of age at the time of admission to the Veterinary Teaching Hospital. SBA concentrations were determined enzymatically and by radioimmunoassay. Total and direct bilirubin and triglyceride concentrations were measured, as well as sorbitol dehydrogenase (SDH) and gamma-glutamyltransferase (GGT) activities.


RESULTS
There was a significant negative correlation between age and SBA concentration. Compared with mature horses, SBA concentrations were significantly greater in healthy foals at each collection time over the first 6 weeks of life. Radioimmunoassay values were lower than enzymatic SBA values, with increasing bias as the mean difference between values increased. When comparing age-matched values between healthy and ill foals, there were no significant differences in SBA. None of the ill foals had a primary diagnosis of hepatic disease. There was no significant correlation between the SBA concentration and the bilirubin or triglyceride concentrations or the GGT activity. There was a significant direct correlation between increased SBA and serum SDH activity in healthy foals only.


CONCLUSIONS
SBA concentrations in foals are significantly higher in the early neonatal period, underscoring the importance of using age-matched references when evaluating clinical pathology values during the neonatal period.
Barton
Michelle Henry
MH
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA. mbarton@vet.uga.edu
LeRoy
Bruce E
BE
D000375:Aging / Q000097:blood; D000818:Animals; D000831:Animals, Newborn; D001647:Bile Acids and Salts / Q000097:blood*; D016638:Critical Illness; D003430:Cross-Sectional Studies; D006734:Horse Diseases / Q000097:blood* / Q000175:diagnosis; D006736:Horses / Q000097:blood*; D007064:L-Iditol 2-Dehydrogenase / Q000097:blood / Q000378:metabolism; D008107:Liver Diseases / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D011446:Prospective Studies; D011863:Radioimmunoassay / Q000379:methods / Q000662:veterinary; D005723:gamma-Glutamyltransferase / Q000097:blood / Q000378:metabolism
D001647:Bile Acids and Salts; D007064:L-Iditol 2-Dehydrogenase; D005723:gamma-Glutamyltransferase