The pulse beat of your dog is most conveniently found on the inner aspect of either hind leg, a few inches above the knee joint. As you feel the inside of the leg at this point, you will find a shallow groove in which the large femoral artery and vein lie.
With gentle pressure from your fingertip you will feel the arterial pulse that corresponds to each contraction of your dog's left ventricle. Using a watch, time the number of pulse beats for 15 or 30 seconds, and multiply the number of beats by either 4 or 2, as appropriate to know the pulse rate per minute.