The usual interval
A shod horse is commonly reset every five to eight weeks. Six weeks is the number a lot of barns pencil in, then adjust. The hoof wall grows the whole time the shoe is on. Leave it too long and the toe gets ahead of the foot, the shoe sits where it no longer matches the hoof, and nails start to work loose.
A barefoot horse is not on a longer schedule by default. Trimming is still a cycle. Many barefoot horses are seen every four to six weeks because there is no shoe holding the edge together while the wall grows.
What moves the date
Work, footing, and the individual hoof matter more than the breed label on the papers. A horse in arena sand, a horse living on wet Kentucky pasture, and a horse hauling across Texas caliche will not grow and wear the same way. Season matters too: wet spells soften the wall, and a dry spell can make it brittle.
Young horses, horses coming back from an abscess, and horses that just changed jobs often need a shorter gap for a few cycles. A horse that throws a shoe in the first two weeks is telling you something about fit, schedule, or the way that foot is used. Waiting for the next lost shoe is a poor calendar.
Signs the cycle is too long
Look at the toe from the side. If it is running forward, the heels are crushed under the shoe, or the clinches are risen, the visit is late. Cracks that were not there last month, a shorter stride, or a hoof that looks flared past the shoe are reasons to call before the standing appointment.
The farrier who sees the foot every cycle is the right person to set the interval. A directory listing, including one on this site, is only a way to find someone who travels to your county. It is not a diagnosis.
How to keep the schedule
Book the next visit before the farrier leaves the driveway. Write the date, what was done on each foot, and anything they want watched. The shoeing log printable on this site is a paper version of that habit.
If you are new to a county, ask when they are already in the area. A farrier who can fold you into a loop is more likely to stay on a six-week rhythm than one who has to make a special trip from two hours away.