h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

although it could be argued Horsehunt is a more sensible if less pleasing name....

It would be possible to read a little more into this than I actually intended. It's not one of my 100% satires where every sentence is a carefully aimed blow to the victim's credibility. If it had been, I'd have had the dragonriders dressed up in silly costumes for a start.
It's just an interesting coincidence that the horse is the perfect subject for the hunt.

On another world, (perhaps in another universe,) Dragons are fairly commonplace. The dragons and their riders protect the inhabitants of this world, and in return the inhabitants provide the riders and dragons with food and supplies from their farms and mines. The dragons get by nicely on the meat provided in the form of various ox-like creatures, but the creatures are fat and slow, and occasionally the dragons and their riders hunger for something a little more exciting.
The weyr provides a fast horse, and it is set loose, usually in a forest, woodland or gully. A number of dragons and their riders then launch from nearby, and begin to pursue the horse. The horse, of course, has no idea what is happening, but its first and very sensible reaction is to run. The dragons are not permitted to breathe fire, and so a horse moving at speed through thick forest is actually a difficult target even for the strongest of dragons. If the horse is foolish enough to leave the protection of the terrain it has been provided with, it will be struck down immediately, but the hunt can last for as long as an hour. The dragons, of course, have more stamina than even the healthiest of horses, and there is great excitement in the repeated swooping down on a rapidly moving but partially obscured target, which the dragons and riders relish. Eventually, in most hunts, the horse will become tired, enter a clearing, leave the gullies, or a dragon will manage to breach the thick woodland. The horse will then have its neck or legs broken by a dragon's foot or jaw, or perhaps its side will be ripped open by the dragon's spur. Either way, the horse is then devoured by the dragons who caught it- horses are lean animals, and although tough, this is not a problem when you've got teeth up to three feet long and a belly full of fire. The wing then returns to the weyr, usually to tell exaggerated stories of mid-air near misses and potentially injurious dives, as dragonriders tend unavoidably to develop somewhat inflated egos.

Yes, this is somewhat McCaffrey based, well spotted

You know there is no more humain way to kill horses, and it is entirely neccesary to some holders who own chickens.