Abstract:ObjectiveThe aim of this study was to observe the effect of postural changes on autonomic nervous control of heart in Beagle dogs. Methods Electrocardiogram (ECG) was recorded in static posture (lying, standing, sitting and hanging) and moving posture (walking) from conscious and unrestrained female Beagle dogs using a non-invasive telemetry system, and the autonomic nervous function was investigated by power spectral analysis of heart rate variability (HRV). ResultsIn static postures, the RR interval, SDNN, RMSSD, pNNabs (50), total power (TP), very low frequency (VLF) power and normalized high frequency (HF) power were significantly higher than those in moving posture (P<0.05, P<0.01), while the heart rate, normalized LF and the LF to HF ratio were significantly lowered (P<0.05, P<0.01). Conclusions The parasympathetic nervous activity is dominant in static state of different postures, while sympathetic nervous activity is dominant in moving state. Postural changes can influence the heart rate and inevitably affect the cardiac autonomic nervous control. It depends on the intensity of the vagus nerve activity, and leads to the disturbance of LF/HF balance.