“I have to pee like a racehorse.”
As for horses, they pee up to two gallons daily. But racehorses actually pee LESS than regular horses. That’s because racehorses get fed a lot of dry grains while regular horses graze on sweet, succulent grass with dew on it… Uh-oh, gotta pee!
So that means before a race, you’d see a bunch of horses peeing their brains out. And you get people saying they have to piss like a racehorse.
What stinks is that although this is totally uncool, it is still allowed in big horse races today. So, are the people in charge of races like the Kentucky Derby idiots? Maybe. I say we put some diuretics in their iced tea and see how THEY like peeing like a racehorse!
Good info on this topic at the Explainer.