The 'Luminarias': Outdated Cruelty?

Happy horse??? Methinx NOT!!!

Every year on 17th Jan., the righteous people of San Bartolome de Pinares in Spain celebrate St.Anthony the Abbott, patron saint of domestic animals.
They don't don their best bib and tucker, head to church and pray. Instead, they ride their horses, donkeys and mules through piles of burning branches! As you do.
This hamlet has a population of 627 but its numbers swell as riders descend upon it to take part in what is known as the 'Luminarias'. This traditional festival dating back 500 years is supposed to purify the animals with the smoke of bonfires. Yes, the horses are actually riden through the flames as well as the smoke. It is believed to protect them against illnesses for the year to come.
The men and women of San Bartolome de Pinares gather all the branches they find in the days leading up to the festivities, and when dusk falls on the eve of Saint Anthony's, they set them ablaze. Riders lead their mounts through the burning piles, accompanied by the sounds of drums and Spanish bagpipes.
Animal rights activists don't buy the whole purification deal, but in a country like Spain, where barbaric traditions like bullfighting and Toro Jubilo still persist, they don't have high hopes of putting an end to it. Plus, the owners say their animals remain unharmed by the flames... riiiiiggghhhttt!!!
With St Anthony being one of the patron saints of animals, I can't

The REAL motivation...

somehow imagine the sainted gentleman seeing any spiritual merit in subjecting horses to this fearful ritual.
Perhaps in the Middle Ages, the 'smoke purification' idea may have had some validity, smoking any mites and ticks off the horses - who knows? But in the modern world, there surely must be a way to modify the tradition so horses are perhaps blessed by a priest, without being abused like this..?