It's no fun to see an innocent, crazed, animal tortured before a screaming crowd of people, who should be hanging their heads in shame. But even if you leave after 15 or 20 minutes, the damage has been done. Your money has gone to support this hellish business, which humane organizations are working to end.
Various things are often done to weaken a bull before the bullfight. Handlers have filed down bulls' horns to the tender quick, put laxatives in their food and drugged them. They have stuffed wet newspapers up bulls' nostrils and into their ears and rubbed Vaseline into their eyes to blur their vision.
The horses used in bullfights are old and usually drugged. Often, wet newspaper is stuffed in their ears and their vocal cords are cut, so the audience won't hear their cries. They wear long blankets to hide their entrails, which spill out when they are gored and disemboweled.