These are three essential elements to the run.

The oxen, are of a special type - animals which have been castrated, and their function is to pacify the bull and guide him towards the bullring. They are familiar with the route and they keep the bulls grouped in a tight bunch. They help to avoid those dangerous situations which arise when a bull gets separated from the group. Eight of them are released from the pen along with the bulls when the rocket goes off to indicate that the run has begun. A few minutes later, three more gelded oxen are let out of the pen for the purpose of "sweeping up" any bull which might have become separated along the route. The heifers are meek animals who won't attack with their horns. But they are big ungainly animals and they, too, can often be the cause of some heavy bruising as they step over the fallen bodies along the route. Their big awkward horns can often unintentionally graze the bunched-up runners and cause some sore bruising. Keep them at a respectable distance while you are doing the run. The same rules apply to them as to the bulls - no touching, distracting or mistreating of them is allowed during the run. They have an important function and must be let do their work.

The drovers are those persons you see who come running out from the pen just behind the bulls carrying their long thin rods. Along the route at certain points they are being continuously relieved by others as the pace is much too fast for the same men to cover the whole route. Their principal function is to try to keep the bulls in a compact group. They are absolutely necessary to the run, particularly when there is such a tight mass of runners. They use their long rods to keep the bulls in line and stop them from straying. They won't hold back from taking a swipe at any runner they might see who is touching or distracting the bull in any way. And a hefty swipe from one of those rods can hurt - so, be warned. If you don't believe me, just ask my friend Kirio...

The "dobladores" , or guiders, are four men who are waiting inside the arena for the arrival of the bulls and who, using their red-coloured capes, coax the bulls towards the pen on the far side of the ring. Their work is particularly important should one of the bulls be loose and separated from the group. Without their work there would be many more serious accidents in the ring because the runners are totally defenceless once inside the wide open space of the arena and this is why it is so important that they head for the safety of the barriers on the sidelines as soon as they burst into the ring.