What is the normal resting heart rate of an adult horse in beats/minute?

The normal resting heart rate for an adult horse typically falls within the range of 28 to 40 beats per minute. This range is established based on physiological studies of horses, which show that their cardiovascular system operates efficiently at this heart rate during rest.

At this rate, the heart is able to adequately supply oxygenated blood to the muscles and organs without putting undue stress on the cardiovascular system. A heart rate outside this range could indicate potential health issues or stress in the horse.

In contrast, the other ranges provided do not align with the established norms for adult horses; for instance, a resting heart rate of 10-20 beats per minute is too low and would suggest severe bradycardia, which can be life-threatening. Similarly, rates of 20-30 and 40-60 would either be on the low side or suggest a state of high activity or stress, which is not typical for a resting horse. Thus, the range of 28-40 beats per minute accurately reflects the normal resting condition for an adult horse, ensuring the animal is healthy and well-regulated in its cardiovascular functions.