A quality stethoscope will reduce a lot of frustration. The higher the quality of your stethoscope, the easier to hear heart sounds. The best location to auscultate the heart rate in a horse is behind the left elbow on the lower chest. Sometimes it is necessary to have the horse step forward, as the point of the elbow may be over the area that you need to place your stethoscope head.
The following audio file is a resting heart rate that is auscultated on the left side, just behind the elbow. For the best effect – use head phones and continuous play.
Normal equine heart rate is approximately 40 beats per minute. A normal equine heart beat as 2 distinct sounds – “lub” then “dub”. The “lub” or first sound is the closure of the atrioventricular Valves (mitral and Tricuspid). The “Dub” or second sound is the closure of the aortic and pulmonic valves. Do not confuse the 2 sounds as two separate beats. The two distinct sounds can always be heard in a calm resting horse. Sometimes, a beat will be dropped or missed – which is normal:
The two distinct heart sounds become less obvious as the heart rate increases. An increased heart rate will occur with excitement, exercise and pain.