Once a year, the horse inspector comes to the area and inspects all of the horses there, for a set fee, perhaps 1 GP per head. The Inspector keeps an account of how many horses there are, and what type. Animals deemed in poor health, or a hazard to other horses are put down. (Coggins Testing, Mandatory in the US, failure to have a valid Negative Coggins test can result in Federal fines, as well as criminal prosecution) This also serves the purposes of raising money for the local lord who sponsors the inspector as well as keeping an eye on less that loyal lords who might think to enlarge their cavalry horse, and warhorse stock.
Wheel Tax - carriages and wagons are issued a certificate of taxation once a year by the tzx assesor. Failure to produce this paper, or possession of an expired one requires the immediate payment of the wheel tax. The more ornate, or heavy the carriage is, the heavier the tax. a small two person buggy would be inexpensive, perhaps a 2 to 3 GP, while the six horse drawn, gold inlaid, rocker spring eight person grand salon Carriage will set the owner back perhaps 15 to 20 GP a year. Produce wagons, and hauling carts run at a set rate of 2 GP per pair of horses. This money is nominally used to keep the roads of the kingdom, primarily in the cities, in good repair.