Provided is a method for detection of a preselected condition such as subclinical stress or pain in a subject animal using heart rate variability. The method comprises the steps of determining a heart rate and/or inter-beat interval for the subject animal over a preselected period of time to determine the subject animal's heart rate data. The method further comprises analyzing the heart rate or inter-beat data from the subject animal to identify a set of heart rate variability data for the subject animal for a selected heart rate variability parameter such as a frequency domain or time domain parameter such as LF/HF ratio. The heart rate variability data from the selected animal can be compared to substantially normal values established for the selected animal species or compared to the subject animal's own previously identified substantially normal values or HRV pattern over a period of time and thereby determine whether the preselected condition exists.
NOVEL UTILIZATION OF HEART RATE VARIABILITY IN ANIMALS