A normal resting horse has a heart rate of 38-40 beats per minute, foals (70-120 bpm), yearlings (45-60 bpm) and 2 year olds (40-50 bpm). Maximum heart rates can exceed 180 beats per minute, but a rate above 80 should be considered serious in most non-exercising horses.he average respiration rate of a mature horse at rest is 8-15 breaths per minute. A horseâs respiration rate increases with hot or humid weather, exercise, fever or pain. Rapid breathing at rest should receive veterinary attention, and keep in mind that the respiration rate should NEVER exceed the pulse rate.