A Percheron saddle fitting fails in one direction more than any other: saddles built for riding horses are simply too small in every dimension, and the failure hides because the saddle still sits on the horse, after a fashion, while bearing on a fraction of the area it should. Percherons are among the largest horses routinely ridden, tall as well as broad, with flat, wide backs and shoulders built for collar work. The checks below protect against the perched, pinching fit: genuine draft width, panel contact across the whole bearing surface, spine clearance under real load, and stability in front of a shoulder that moves like machinery.
Tree: draft-shaped or not at all
Judge the tree by what the saddle does ungirthed. On a Percheron, a correct draft or hoop tree lets the saddle settle down onto the back, seat level, panels meeting the back along their length. A riding-horse tree, even a wide one, often has the wrong shape: its rails curve for a narrower, more peaked back, so on a Percheron it contacts at the edges of its panels and bridges across the spine, or tips and pinches at the points. Look along the saddle from behind and compare its spread with the spread of the back. If the saddle looks like it is visiting the horse rather than belonging to him, believe your eyes and change the saddle, not the padding.
Panels: area is the whole argument
The physics of draft riding is area. A rider's weight on a Percheron should be spread over the widest, longest panels the back can accommodate within the ribcage, because the pressures under small panels on a big horse are how backs get sore despite the animal's strength. Run your hand under the girthed panels, front to back and side to side: contact should be broad and even, without a floating middle or hard front edges. Check the panels end ahead of the loin, since even on this scale of horse the bearing surface stops at the last rib.
Clearance under a heavy horse's real load
With a broad, flat back, the risk is the saddle spreading and settling down onto the spine and withers once a rider is up and the horse is moving, so clearance checks happen mounted and after work, not just in the yard. You want daylight along the gullet throughout, a channel genuinely wide enough for a draft spine, and wither clearance that survives the horse working in an outline. The girth will be long, its groove close behind massive forelegs, and a saddle dragged forward by girthing will jam its points into the shoulder: check where the saddle sits after ten minutes, not where you placed it.
Shoulder and stability
The Percheron shoulder is built to lean into a collar, and under saddle it swings a long way. Watch at walk and trot for the saddle being shoved backwards, rocking over the shoulder's movement, or migrating sideways on turns, and have a watcher behind you. Sit the saddle far enough back that the shoulder travels freely while the panels remain on the ribcage, a balance that on this breed may look further back than riding-horse habit suggests.
Keep the specification, because replacements are rare
Draft saddles that genuinely fit are uncommon enough that the specification of yours is valuable information. KinsLe's Pet Passport keeps your Percheron's tree type, panel details, and fitting notes together with his records in one portable packet, so if the saddle is ever damaged or his shape changes with age and work, the search for the next one starts from measurements known to suit him.