use your 2 fingers as if you were pointing a hand gun and not your thumb as this has a pulse of its own ---- I made this mistake and though my horse had chronic lami lol
also if you can't feel it, vary how hard you press, sometimes you press too hard and cut it off, others you don't press hard enough to create the resistance to feel it
Lotty, just looked at the link you posted, the guy was using his thumb to feel the digital pulse. As another poster says the thumb has a pulse which can make you feel more than the horses pulse. I would use my finger.