Electrointestinography, ultrasonographic contractility, and borborygmi of the cecum and colon are not altered by a single episode of hand walking exercise in healthy horses.

Abstract

To evaluate the effect of hand walking exercise on myoelectrical activity and contractility in normal, healthy horses. Prospective experimental design. A convenience sample of 8 horses were randomized to a control or hand walking treatment group; each horse underwent both treatments. After a 30-minute baseline electrointestinography (EIG), horses were stall rested or hand walked for 15 minutes. Electrointestinography was repeated immediately and at 2 hours. Ultrasonography and auscultation monitored cecal and left ventral colon (LVC) contractions during EIG. Electrointestinography spectral analysis obtained dominant frequency (DF), dominant power (DP), total power (TP) frequency distribution, and changes in slow-wave rhythmic activity. The median (IQR) DF in cycles per minute (cpm) was higher for the cecum (2.067 cpm; IQR, 0.633 cpm) compared to the LVC (2.0 cpm; IQR, 0.396 cpm) but was unchanged by either treatment. Cecal DP (0.0086 mV; IQR, 0.0070 mV) was higher than LVC DP (0.0068 mV; IQR, 0.0051 mV) in the hand walking group, but DP and TP were unaffected by either treatment over time. Borborygmi at all time points were unchanged in both treatment groups. Ultrasonographic contractions were similar across time in both treatment groups and correlated with borborygmi (ρ = 0.63). Dominant power did not correlate with contractions or borborygmi (P > .2081). Brief hand walking as a single strategy to increase gastrointestinal motility did not affect contractility or EIG in normal horses. Fasting and stall rest may not represent the spectrum of severity of gastrointestinal stasis observed in clinical cases. This model is directly applicable to horses fasted prior to surgical procedures.