Large Animal Medicine Resident Cornell University Ithaca, New York
Bile Acids (BA) are markers of hepatic function. In equine practice they are commonly used to establish severity of liver disease and monitor response to treatment. Recent published data from Europe supports the use of BA as prognostic indicator of short and long-term outcome in horses. Similar studies are not available in the United States. Etiopathology of hepatic diseases in horses from United States might differ from horses included in the European study causing predictive outcome value of BA to differ. Determining the prognostic value of BA in a population of horses with liver disease from Eastern United States might therefore provide a more accurate prognostic information for this marker in horses in this region. Our hypothesis was that moderately to severely increased BA values are not correlated with outcome in the population considered. The objective of the study was to retrospectively evaluate the predictive value of elevated BA on outcome in a population of horses presented to four referral hospitals in the Eastern United States. To test our hypothesis, we determined if BA values differed between survivors and non-survivors. Moreover, GGT, and direct bilirubin (DB) were also evaluated in the studied population. Records of horses 1 or more years of age admitted to four referral centers between 1997 and 2018 with a BA measurement > 30 μmol/L and at least 6 months follow up information were included in the study. Four of these horses were research horses. The highest single BA, GGT and DB value recorded for each horse was used for statistical analysis. BA, GGT, and direct bilirubin values were compared between survivors and non-survivors. Eighty-two horses met the inclusion criteria. These horses presented for liver disease. 55% of the horses survived at least 6 months post-discharge. BA values were not significantly different between survivors and non-survivors (P=0.45). BA and GGT or Direct Bilirubin were not correlated. In the population evaluated GGT values were also not correlated with outcome (P=0.15), instead direct bilirubin values were negatively correlated with outcome (P=0.0). According to these results, BA values do not represent a reliable long-term prognostic indicator across the different liver pathologies for this population of horses with liver dysfunction from Eastern United States. Instead DB values may be more reliable indicator of prognosis in a similar population of horses.