2017 ACVIM Forum Research Abstract Program

The absolute changes over time revealed no pattern of change over time. The mean PFCB was 2.8% AE 7.96% (CI À2.88%, 6.99%). There was not significant evidence (P-value of 0.5056) of a time effect using the repeated measures model. There was no evidence of any significant time effect on the level of ACTH in PPID + or PPID À (non-PPID) horses. There did not appear to be any systematic degradation of ACTH level due to delay in measurement through 36 hours post collection. The results of this study supports the recommendation that immediately chilled EDTA blood samples (properly stored) may be centrifuged and plasma separated within 36 hours of collection for shipment to the respective laboratory for analysis without degradation of the ACTH level. Further research is needed to determine ACTH stability in a larger number of horses (PPID+ and PPID À ) from separate sites and different geographic regions. The purpose of this study was to investigate effects of systemic corticosteroid administration on circulating ACTH and cortisol concentrations in healthy horses and horses with Pituitary Pars Intermedia Dysfunction (PPID). The hypothesis of this study was that administration of synthetic corticosteroids would decrease circulating ACTH and cortisol concentrations in healthy horses while significant changes would not be detected in horses with PPID.