To my knowledge, docking tails in horses is illegal in the UK so I guess they just show the horses naturally.
But in the States, or wherever else you're all from, what's the deal with docking? Do show horses HAVE to be docked? Can they enter a show with a full tail - both in-hand, driven and specialised draft horse shows?
Regarding working drafts, is it truly necessary to cut off their tail, or can the horse work and log with a full tail?
Do you dock your draft's tails?
In the US, you do not have to dock a draft's tail to show them but depending upon the level you show at and/or who you are being judged by, you are at a disadvantage before you enter the ring if you don't. It's simply traditional for them to be done and most draft people can't wrap their heads around the fact that it doesn't change the comformation, quality, action or training if you leave it. I do not dock tails but when I show their tails are braided up so their back legs are completely visible.
In hitch and halter classes it's rare to see horses with long tails. Part of that is they are hitch horses. They need to look like the other 5 or 7 in the hitch. Unless you raise every horse in your hitch, it's unlikely you will come across that perfect horse for sale with a tail. If you are raising them, you dock the tail for the future owner who would otherwise pass on them because they have a tail and don't fit in their the hitch.
In farm classes (obstacle driving or races) and pulling classes about 50% will have tails. The biggest argument for docking tails is they get caught in the lines, pto or other farm equipment they are pulling. The irony is most of the horses that complete in farm classes also work for a living. They work the downtown malls, they do weddings, they cut and rake hay, they log, they plow... and their tails don't pose a problem. The hitch horses on the other hand are shod in shoes during the show season that don't allow them even turnout time much less slogging around in the mud.
Again in the US you are more apt to come across Clydes and Shires who have tails, Percherons and Belgians, less so. Brabants and American Creams never have their tails done.