https://www.facebook.com/reel/497525892869004
I left a link there on what those races are, the video is actually from where the screenshot was taken.
Here is another one:
https://www.tiktok.com/@vincent_zs/video/7283072654435765506
The UK is full of those events, it's just a small gated track probably less than 50 meters with or without small obstacles and the ducks are let loose from their cages with somebody walking behind them to encourage them to go on, there are no whips or other things, it's farms animals and they are used to being guided by humans to either food or their shelter so they just go and follow the track.
There are plenty of other activities at those rural fairs, I'm quite amazed by people being amazed at their existence, they've been around for ages, one of the funniest but also boring happening around her is the carrot finding competition where some rabbits are released in a pen and the first one getting to a hidden carrot is the winner.
It doesn't always have to be for a charity but most are, the way it works is that everyone gets a ticket for $x and the "winner" gets a toy or plushie, I don't recall a single event like this nor in my town or somewhere else when it was real betting with odds and stuff like this, first you would need a gambling license for it and nobody would go through all that trouble.