Things You'll Need
- Watch with a second hand
Instructions
Permit your veterinarian to perform a transabdominal ultrasound test during your mare's final trimester of pregnancy -- usually considered the last 3-1/2 to 4 months of gestation. This test allows you to pinpoint the closest approximation to the fetal heartbeat and tells you where to place your stethoscope on the mare's abdomen.
Place the ear tips of your stethoscope into your ears, seating them in the deepest part of the outer ear canal leading to your eardrum. You may need to twist the ear tips away from your body to accomplish a tight fit.
Rest the diaphragm -- the bell at the end of your stethoscope -- on your mare's belly at the spot where you noted the heartbeat on the ultrasound. Adjust the positioning until you hear the heartbeat.
Count the number of heartbeats for 15 seconds using the second-hand timer on your watch. Multiply that number by four to get the total number of heartbeats per minute.