Peritoneal bile acids concentration in adult horses with hepatic and gastrointestinal disorders

Background: Peritoneal bile acids concentration (PBAC) has not been previously reported in horses. A case of liver lobe torsion in which increased PBAC was detected prompted us to study PBAC in horses. Objectives: (a) To determine a reference range of PBAC in horses; (b) to compare PBAC from horses with either hepatic or gastrointestinal disease and healthy horses and (c) to assess the prognostic and diagnostic values of PBAC. Study design: Prospective case-control. Methods: Prospective observational clinical study. Bile acids concentrations were measured in both plasma and peritoneal fluid in selected clinical patients with hepatic or gastrointestinal disease (n = 108) and healthy horses (n = 11). Sixty-eight of 108 patients survived to hospital discharge, and the remaining 40 were nonsurvivors. Additionally, other haematological and biochemistry analyses were performed. Results: Sick horses were classified according to diagnosis into hepatic (n = 13), gastrointestinal (GI) obstructive (n = 48) and GI ischaemic-inflammatory (n = 47) groups. The hepatic group had significantly higher PBAC (6.8 [2.3-9.4]; median [IQR]) than the control (1.0 [0.6-1.5]) and GI obstructive groups (1.2 [0.8-1.7] µmol/L; P <.001). Moreover, the GI ischaemic-inflammatory group (3.3 [1.4-5.5]) also had significantly higher values than the control and GI obstructive groups (P <.001). Regarding outcome, the nonsurvivor group (n = 40) had significantly higher median PBAC value than the survivor group (n = 68, 4.1 [1.6-6.5] vs 1.3 [0.8-3]; P <.001). Main limitations: A higher number of horses with abdominal disease is required to confirm the clinical significance of these findings. Conclusions: PBAC may have a role in the diagnosis of hepatic and gastrointestinal disease and as a prognostic tool in horses with abdominal pain.