PROCEDURE
Ensure that the horse is adequately restrained. Be sure that the stethoscope's earpieces are pointing forward before placing them in your ears. Make contact with the horse's left shoulder and move to the left side of the horse.
Place the stethoscope near the girth (lower than the level at which you would buckle the girth) and gently slide the stethoscope towards your horse's head (cranial), sliding behind the big triceps muscle mass and against the rib cage.
Now listen... "Lub" and "dub" are the major heart sounds and together make up a single beat. Count the number of beats in 15 seconds and multiply by 4 for the total beats per minute. When assessing for normal rhythm, listen to the heart for a full 30-45 seconds.
TIPS FOR SAFETY AND SUCCESS
To hear the heart sounds most easily, it is important to push the stethoscope into the rib spaces behind the triceps muscle mass in the left girth.
Until you become practiced, try to listen to the heart in a quiet place, out of the wind. Keep in mind that it is more difficult to hear the heart sounds in heavier or fatter horses.
You can hear the heart beat at the right girth but it is quieter in most horses, and is heard better with the stethoscope head pushed far forward.
Ensure that the stethoscope ear pieces that you put in your ears point forward. Keep in mind that a horse heart beat is made up of a two-part lub-dub sound.
Do not count each lub and each dub as separate heart beats.
A common oversight is not having a watch or clock (with a second hand ) available for this procedure. Make sure you have an adequate timepiece with you when you perform this skill.