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

We observed significant differences in the duration of PR intervals (ms) in the frontal plane and apical-to-basal derivations, and in the QT interval (ms) in both derivations; as well as a significant increase in R wave amplitude. The electrocardiographic parameters of pregnant donkeys diverge in terms of duration, amplitude and morphology in (E39) contrast with other donkey and equine breeds and these findings highlight the importance of obtaining specific values for distinct species, breeds and pregnancy stage so a safer prenatal care can be achieved. Key genes involved in the transport of calcium (Ca 2+ ) across the sarcoplasmic reticulum (SR) encode proteins such as the ryanodine receptor (RYR), which releases Ca 2+ from the SR, and SR calcium ATPase (SERCA), which pumps Ca 2+ back into the SR. Newly discovered regulatory micropeptides such as MRLN, PLN and SLN inhibit SERCA, thereby controlling intracellular Ca 2+ and contractility. The transcript expression or protein abundance of these micropeptides in horses is unknown. The purpose of this study is to determine the relative expression of equine Ca 2+ regulatory genes in left ventricle, right atrium, and gluteal muscle. RNA was extracted from tissues collected from 7 horses and reverse transcribed into cDNA. Transcript abundance was quantified using qRT-PCR and data normalized to GAPDH (within sample). Data was compared using an ANOVA, with gluteal used as a baseline, and results were corrected for multiple testing. Following a single dose, mean maximum concentration (C max ) was 16.61 ug/mL at 1.35 hours (T max ). APAP remained above presumed therapeutic concentrations (10 ug/mL) for two hours postadministration and was undetected by 12 hours. Elimination half-life (T ½ ) was 2.78h. No significant accumulation was noted following multiple doses. Average C max of APAP following repeated oral dosing was 15.85 ug/mL, with a T max of 0.99 hours and T 1/2 of 4 hours. SDH was significantly decreased (pre: 13.84 U/L, post: 10.52 U/L, p = 0.013) and total bilirubin was significantly increased (pre: 1.99 mg/dl, post: