2018 ACVIM Forum Research Abstract Program: Seattle, Washington, June 14 - 15, 2018

Mean ACTH level at Day 0 for plasma stored between ice packs at -20 C was 392.2 pg/mL that declined 1.1% to 387.9 pg/mL by Day 7. No significant degradation (p = 0.4860) of ACTH was observed by Day 7. None of the storage methods resulted in sample degradation that differed significantly from baseline. Trends toward degradation were observed on Day 90 in -80 C stored samples and on Day 60 at -20 C stored samples. No significant degradation was observed in ACTH from plasma samples stored between ice packs at -20 C for 7 days. Freezing plasma for short periods of time at -20 C or at -80 C for at least 90 days resulted in no statistically significant degradation of plasma ACTH compared to non-frozen plasma baseline samples. Further studies should be conducted to further evaluate the effects of freezing on plasma ACTH concentrations in larger populations of horses. The aim of the study was to evaluate the effects of weight gain, achieved by providing healthy horses a low-carbohydrate and fat rich diet followed by pasture, on insulin sensitivity, blood pressure and serum cortisol concentrations.