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Thiamine is a vital co-factor for several anti-inflammatory and antioxidant processes that are critical for mitigation of sepsis-associated inflammation, but pharmacokinetic (PK) analysis has not been reported in horses. We hypothesized that IV thiamine hydrochloride (TH) at increasing dosages would result in corresponding increases in plasma thiamine concentrations without causing adverse effects. A randomized cross-over study was performed in 9 healthy horses that each received TH at 5, 10, and 20 mg/kg IV. Blood was collected immediately prior to drug administration and at several time points thereafter. High-performance liquid chromatography with mass spectrometry was used to quantify thiamine concentrations at each time point. Non-compartmental PK methods showed that IV TH resulted in supraphysiologic plasma concentrations with a short half-life (0.77-1.12 h) and no adverse clinical signs were observed. The terminal rate constant decreased as the dosage increased (p < .0001) and clearance significantly decreased at the 20 mg/kg dosage (p = .0011). The area under the curve (AUC) increased in a non-linear fashion. These findings suggest that thiamine follows non-linear elimination kinetics in horses, which is likely due to saturation of renal elimination. Future studies are needed to identify therapeutic plasma concentrations and develop thiamine dosing recommendations for horses.

Background In metabolically stable horses, alpha‐2‐agonists suppress insulin secretion with transient hyperglycemia and rebound hyperinsulinemia. In horses with insulin dysregulation (ID), the effect of alpha‐2‐agonists has not been investigated; however, both the alpha‐2‐agonist‐induced suppression of insulin secretion and rebound hyperinsulinemia could have clinical relevance. Hypothesis/Objectives In horses with ID, alpha‐2‐agonists will alter insulin and glucose dynamics. Animals Seven horses with ID and 7 control horses. Methods In this randomized crossover study, xylazine hydrochloride (1.1 mg/kg) or detomidine hydrochloride (30 μg/kg) were administered IV, and blood was collected for glucose and insulin concentrations at 0, 15, 30, 45, 60, 90, 120, 150, 180, and 300 minutes after administration. Horses received each drug in a random order with a 24‐hour washout period between drugs. Percent change in glucose and insulin concentrations was compared between groups, drugs, and over time with P

Objective To determine the influence of needle gauge, syringe volume, and syringe size on needle tract leakage after injection in porcine jejunum. Study design Ex vivo experiment. Sample population Three hundred sixty jejunal segments from 20 feedlot pigs. Methods Fresh porcine intestines were divided into 5-cm or 10-cm segments and randomly assigned to the one of nine treatment groups: 25-gauge, 22-gauge, and 20-gauge needles attached to full 12-mL, half-full 20-mL, and full 20-mL syringes (n = 20/group). The jejunal segments were occluded with Rochester-Carmalt forceps prior to injection of diluted India ink. Injection time and leakage were noted by a blinded observer. Multivariate analysis was used with segment size, needle gauge, volume infused, time to inject per milliliter, and syringe size as variables. Results Leakage occurred in 36% of 5-cm and 15% of 10-cm segments and was immediate without palpation in 33.8% and 11% of segments, respectively. Protective effects were seen for 22-gauge needles in both 5-cm (P = .002) and 10-cm (P = .001) segments, whereas injection of 20 mL had a higher odds ratio of leakage compared with injection of 10 mL and 12 mL in 5-cm segments (P = .003). Conclusion Injections with 22-gauge needles reduced the frequency of leakage, while 20 mL instilled in 5-cm segments increased the frequency of leakage in intact segments of porcine jejunum. Clinical significance Injection with a smaller syringe size attached to a 22-gauge needle through a 10-cm segment of small intestine may lower the frequency of leakage from the injection site, but influence on the detection of surgical site leakage remains unknown.