A first viewing has a limited, honest purpose: to screen a horse for reasons to walk away, or reasons to proceed to a veterinary pre-purchase examination. It cannot pass a horse as sound, and you should distrust any viewing, including your own, that claims to.
Body First: Condition, Lumps, Scars and Muscle
Start with him standing square on level ground, in daylight, before anyone rides or lunges him. Stand back and take in his overall condition: whether he carries weight evenly, whether his outline looks balanced, and whether he stands resting one leg in a way that looks habitual rather than relaxed.
Then work over him by hand as well as eye. Run your palms along his neck, back, hindquarters and down each leg, feeling for lumps, scars, swellings, heat and old injuries that a coat can hide from a standing look.
Compare muscle on both sides as you go. A horse who is markedly more developed on one side, or who flinches at the same point in the back or girth area each time your hand passes, is showing you information a ride might mask.
Feet Next: Shape, Shoes, Heels and Frogs
Ask to pick up all four feet, or have the seller do it while you look closely. Check the shape of each hoof: whether the feet form a reasonably matched, balanced set, whether the walls show cracks or flares, and whether one foot is a visibly different shape from its pair, which can point to a long history of favoring the other leg.
If he is shod, look at how the shoes sit: even, tight, and appropriate to the foot, with no risen clenches or a shoe worn dramatically thin on one branch. Look at his heels for height and support, because collapsed, underrun heels change how the whole limb loads.
Pick the feet up in the same spirit as the body check: you are judging care and obvious structure with your eyes, not delivering a verdict on his future soundness.
Movement Last: Walked, Trotted and Turned
Watch him move on firm, level ground, because a soft arena surface hides unevenness generously. Have him walked away from you in a straight line, then back toward you, watching how each foot lands and whether his hind feet track into the line of the front ones.
Then have him trotted in the same straight lines, away and back, on a loose rein so his head is free. Watch for an even rhythm, level hip movement from behind, and a head that stays steady rather than nodding with one stride. Finally, have him turned both ways in a small circle, left and right, and watch how he places his feet and crosses his legs; reluctance or scrambling on one rein and not the other is worth noting exactly as you saw it.
Note what you observed in plain words on the day: not diagnoses, which are not yours to make, but observations, which are. If he passes your screening, the essential next step is a veterinary pre-purchase examination, and the veterinarian will examine him with equipment, flexion tests and a depth of training your viewing deliberately does not attempt.
Reading His Records Around the Viewing
What you see in an hour should sit alongside what his history says over years. His records reach you through the Transferrable Profiles system on KinsLe, handed over by the seller for a horse genuinely for sale, and you should read them around the viewing: before you travel, so you know what to look for, and again afterward, so you can set what you felt under your hand against what the record describes.
Handled that way, a viewing becomes a disciplined hour rather than a hopeful one. If you buy him, his history stays attached through the Transferrable Profiles record on KinsLe, and the notes you studied become the opening chapter of his care with you.