According to the horse's trainer, it had escaped from the stable of the racetrack located nearby. The animal galloped through the streets, and then broke into the bar.
"Between the track and the stables, her rider fell off. The filly escaped by going on to the road, and crossing a roundabout before entering this bar. It is all quite exceptional," he said as quoted by the Ouest France newspaper.
The owner of the bar has shared this video on social media.