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.

Evaluation of an oral direct factor Xa inhibitor anticoagulant in healthy adult horses.

OBJECTIVE: To assess whether an oral direct factor Xa inhibitor (DiXaI) anticoagulant drug used at the low end of the recommended dose in people achieves presumed prophylactic plasma concentrations and does not induce bleeding in horses. DESIGN: Experimental study. SETTING: Field study. ANIMALS: Ten healthy adult horses. INTERVENTIONS: A DiXaI was administered at a dose of 0.125 mg/kg every 24 h orally for 4 days. Following a wash-out period of 2 weeks, 8 of 10 horses received daily subcutaneous doses of a low molecular weight heparin (dalteparin) for 4 consecutive days at 50 IU/kg. In both trials, antifactor Xa activity was measured at baseline time and 3 hours after each dose administration. Activated partial thromboplastin time, prothrombin time, hematocrit, erythrocyte agglutination, and platelet aggregation were monitored throughout the study. In addition, an in vitro spiking experiment was performed to demonstrate anticoagulant activity of this DiXaI in horse plasma. MAIN RESULTS: When treated with the DiXaI, this group of horses did not achieve the suggested thromboprophylactic plasma range of antifactor Xa activity (0.1-0.2 IU/mL), except for 1 horse after the first administration of the drug. In contrast, median values of plasma antifactor Xa activity 3 hours after receiving dalteparin were within the prophylactic range (0.16 IU/mL). No hemorrhagic events or erythrocyte agglutination were observed. In vitro addition of this DiXaI caused a concentration-dependent effect in antifactor Xa activity. CONCLUSIONS: At the low end of the recommended dose in people this oral formulation of DiXaI did not reach prophylactic plasma antifactor Xa activity in this group of healthy adult horses. Further studies are warranted in order to establish the prophylactic dose for horses.

Parallel testing of plasma iron and fibrinogen concentrations to detect systemic inflammation in hospitalized horses.

OBJECTIVES: To determine if plasma iron concentration is different between horses with and without systemic inflammation (SI) and to assess the accuracy for the detection of SI by assaying plasma iron and fibrinogen concentrations, individually or combined. To assess the prognostic value of plasma iron concentration and to describe the progression of plasma iron and fibrinogen concentrations during hospital follow-up, and its relation to SI and survival. DESIGN: Prospective observational study evaluating plasma iron and fibrinogen. SETTING: University veterinary teaching hospital. ANIMALS: Equine patients greater than 30 days of age. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma iron and fibrinogen concentration was prospectively determined in hospitalized horses. Horses were classified into 2 groups: SI and non-SI. Horses were also classified according to clinical outcome. A group of control healthy horses was also included. A total of 135 horses were included in the study. Plasma iron concentration was significantly lower and fibrinogen concentration was higher in the SI group. Nonsurvivors had a mean plasma fibrinogen concentration significantly higher than survivors. The combination of plasma iron and fibrinogen has a high degree of specificity, sensitivity, and accuracy for the detection of SI in horses. Follow-up measurements were obtained in 48 horses. Surviving horses normalized plasma iron concentration during follow-up examination whereas nonsurviving horses had persistently low plasma iron concentrations. CONCLUSIONS: Plasma iron concentration alone is an accurate marker of SI in hospitalized horses. Alteration of both plasma iron and fibrinogen concentrations improves the specificity and positive predictive value for diagnosis of SI. Alteration of either one of both increases sensitivity and negative predictive value. Surviving horses normalized plasma iron concentrations during follow-up period. The combination of plasma iron and fibrinogen concentrations may help in the detection of SI. Follow-up of plasma iron concentrations may provide useful prognostic information.