Stop every three to four hours, and make it a real stop
On a long journey, plan a proper halt every three to four hours — not a glance through the trailer window at a fuel station, but a stop of twenty minutes or so where you get to the horse, open up, and work through the checks. Horses travel under constant muscular effort, balancing against every bend and brake, and they drink far less readily on the move than owners expect. The stops are where the water goes in, the legs get felt, and small problems are caught while they are still small.
Very long journeys also need a longer rest with the horse unloaded somewhere safe, given a proper drink, a feed if appropriate and a chance to lower its head and clear its airways. Whether any given stop is a quick check or a full unload depends on the horse, but the rhythm of regular halts should be fixed before you set out, not improvised when you feel tired.
Water and forage come first
Offer water before anything else at every stop. Some horses refuse strange-tasting water away from home, so carry water from home in containers for the first day, or flavour it consistently, rather than discovering at hour six that your horse has drunk nothing. Note how much he drinks — a horse quietly dehydrating looks fine until he suddenly does not.
Top the hay net up at the same time. Eating keeps gut movement going through the journey, gives the horse something to do, and a horse that has gone off his hay entirely at a stop is telling you something the same way he would at home. Check that the net is still tied safely and has not dropped low enough to trap a leg.
The horse check: legs, breathing, gut
Run your hands down all four legs at every stop, feeling for new heat, swelling or filling, and pick out the feet if the stop allows. Travelling horses stock up behind, and a leg that is hot and puffy at hour four is a finding, not something to drive on and forget. Watch the breathing: it should settle back toward resting rate within minutes of stopping. A horse still blowing hard, sweating heavily or trembling long after the trailer has stopped is not coping with the journey as well as you hoped.
Look in the trailer for droppings and signs he has staled. A horse passing nothing across repeated stops, or refusing water and hay together, is showing you the early picture of travel colic or exhaustion, and that is the point to phone your vet for advice rather than pressing on to the destination. Offer a short walk in hand where it is safe — a few minutes of grazing and stretching does legs, gut and mind good.
The trailer check, before you roll again
Walk the whole rig at every stop. Feel the tyres for heat and check pressures by eye and gauge where you can, look at the hitch and safety chain, test that the lights are still working, and put a hand on the wheel hubs — a hot hub is a bearing asking for attention. Inside, check the partition, breast and breech bars, ramp latches and any hay-net ties, and make sure vents are set for the weather: a trailer that was right at a cold dawn can be an oven by midday.
Only when horse and trailer have both had their checks do you set off. Handing the routine over matters as much as knowing it: a KinsLe Care Pass gives a co-driver or travelling groom the same stop checklist, the horse's water habits and his travel quirks, so the three o'clock checks are done properly even when they are not done by you.