Start from how the foot grows
A horse's hoof grows continuously, and the shoe fitted to it does not grow at all - that gap is what the farrier's cycle manages. Most shod horses settle into a visit every six to eight weeks, while unshod horses need trims on a rhythm of their own, but the calendar is only the baseline. Growth speeds up on rich spring grass and slows in the depths of winter, a young horse's foot is still changing shape as the animal matures, and a foot recovering its balance after a problem may need shorter intervals for a while. The right interval is the one this horse's feet demonstrate, checked against the record rather than the yard average.
Reading the signs between visits
By week five or six the feet start telling you whether the cycle fits. Look for a toe that has grown long and is tipping the horse's breakover forward, risen clinches, a shoe that has shifted or worn thin, flares creeping up the wall and small cracks that were not there at shoeing. Watch how he moves, too - a horse who starts tripping or striking into himself as the cycle stretches is reporting on his feet. If those signs arrive at week five every time, the honest answer is a five-to-six-week cycle for this horse, whatever the rest of the yard is booked on.
Workload wears the other side of the equation
Growth pushes from the inside; work wears from the outside. Miles on roads and hard tracks wear shoes thin long before the foot has outgrown them, while a horse working mainly on arena surfaces may keep his shoes comfortably to the end of the cycle. A step up in work - more competing, more roadwork, a busy season - can pull a shoeing date forward, and a horse resting through injury still needs trims even though he is doing nothing, because the growth does not stop with the work. Tell your farrier about workload changes when you book, not when he arrives, so the appointment fits what the feet have actually been doing.
Book the pattern, not just the appointment
The practical habit that makes all of this easy is booking the next visit before the farrier leaves, then adjusting the interval deliberately as the seasons and the workload change rather than letting it drift. Keep a simple per-horse record - shoeing and trim dates, what was done, how the feet looked, what the work was at the time - and patterns that are invisible visit to visit become obvious across a year. That record also protects the horse when the farrier changes or a vet needs the foot history at short notice. KinsLe's Pet Passport keeps those shoeing dates and growth notes filed with the rest of your horse's records, so the evidence behind his interval is always in one place.