Watch a short video on how Wellington Polo ponies are raised and cared for and the special precaution and preparation taken on into their game days.  Polo ponies play on into their teens.

WATCH: www.plumtv.com/videos/miami-day-life

From Wikipedia:

Polo ponies need to be almost fearless, and not afraid to bump into other horses, and they can't shy at mallets swinging near their heads. They need to be quick and agile so they can turn and follow the ball through its many changing movements.

Polo ponies have their manes hogged before a match and their tails are plaited up. This is done so that the polo mallet will not get tangled. Formerly, their tails would be docked and banged. Today, polo ponies in competition often have their dock trimmed or shaved, and the skirt of the tail is braided and folded up against the tailbone. The braid is tied off with a lock of hair excluded from the braid, or taped, or both tied off and taped.

There are several different quarters in a game and so each rider has one or two horses per quarter, called chukkas. There are usually 4-6 chukkas per match, each lasting 7 minutes.