Clinical implications of high liver enzyme activities in hospitalized neonatal foals

Objective-To determine whether high liver enzyme activities were negatively associated with outcome in sick neonatal foals as compared with foals that did not have high liver enzyme activities. Design-Retrospective case-control study. Animals-147 foals <30 days old with high gamma-glutamyltransferase activity, high sorbitol dehydrogenase activity, or both (case foals) and 263 foals <30 days old with gamma-glutamyltransferase and sorbitol dehydrogenase activities within reference limits (control foals). Procedures-Medical records were reviewed for information on signalment, physical examination findings, and results of hematologic and serum biochemical analyses performed at the time of admission to a veterinary medical teaching hospital. Results-Case foals were significantly more likely to die or be euthanized, compared with control foals (odds ratio, 2.22; 95% confidence interval, 1.28 to 3.85). Case foals were significantly more likely than control foals to have sepsis, and septic foals were significantly less likely to survive than were nonseptic foals. For case foals, other factors associated with a greater likelihood of nonsurvival were higher anion gap and higher logarithm of aspartate aminotransferase activity. When sepsis status was controlled for, the presence of high liver enzyme activities was not significantly associated with outcome. Conclusions and Clinical Relevance-Results suggested that high liver enzyme activities were common in sick neonatal foals, especially foals with sepsis. Foals with high liver enzyme activities were more likely to be septic, and septic foals were less likely to survive than were foals without sepsis. However, high liver enzyme activities alone were not a useful negative prognostic indicator. (J Am Vet Med Assoc 2011;239:661-667)