Why this is a skill, not a spot check
Anyone can be shown where a pulse is. The skill lies in taking the same readings, the same way, on a relaxed horse, often enough that your figures mean something. A single heart rate taken on a stressed, unwell horse tells a vet very little; a page of calm readings from his healthy weeks tells her exactly how far from normal he has drifted. So build the habit in boring times: after grooming, before a ride, on a quiet afternoon. Your horse learns to stand through the routine without fuss, and you learn his personal figures rather than relying on memory.
Heart rate, breathing and temperature
Find the pulse where the facial artery crosses under the jaw, or rest a hand flat behind his elbow; count beats for a full fifteen seconds and multiply by four. A healthy resting adult usually sits between 28 and 44 beats a minute. Count breathing by watching the flank rise and fall, again over fifteen seconds: expect roughly 8 to 16 breaths a minute at rest. Take his temperature with a lubricated digital thermometer held gently against the wall of the rectum until it beeps; most healthy horses read between 37.5 and 38.5 degrees Celsius. Note the circumstances with every set of figures, because a reading taken after travelling or on a sweltering afternoon is not comparable with one taken at rest in his stable.
Gums, refill, gut sounds and skin
Lift his lip and look at his gums: they should be pale pink and moist. Press a thumb into the gum until it blanches, then release and count how quickly the colour floods back; under two seconds is what you want to see. Listen at his flank on both sides for gut sounds, the gurgles and rumbles of a working digestive system, and learn how busy his belly normally sounds. Pinch a fold of skin at the shoulder or neck and watch it flatten back; on a well-hydrated horse it drops almost at once. Work through all of these in the same order every time, so the routine itself becomes quick and neither of you has to think about what comes next.
Record it like it matters
Write down date, time, the three numbers, gum refill, gut sounds and anything unusual about the situation, every single time. The record is the point of the exercise: patterns only appear across entries, and a slow drift in resting heart rate over a fortnight is something no memory would catch. Note which readings were taken by a helper or a new student of the skill, too, because early attempts at the pulse are often inconsistent, and knowing that stops a wobbly figure causing a midnight panic.
When a number earns a phone call
Contact your vet the same day if his resting heart rate stays above the mid-forties once he has settled, if his temperature climbs above 38.9 degrees, or if his breathing is fast and laboured while he stands quietly in cool conditions. A silent belly alongside pawing, rolling or looking at his flanks is an urgent call, not a wait-and-see. Pale, dry or tacky gums, a refill slower than two seconds and skin that stays tented all strengthen the case for ringing straight away. Having his KinsLe Pet Passport hold the baseline readings alongside his other records means you can read the vet his normal figures down the phone instead of guessing while she triages him.