The Greater Manchester Police, Whitefield Division, said they received a call Saturday from workers at a Whitefield McDonald's about a woman on a horse.
The workers said the woman attempted to order at the restaurant's drive-through, but she was refused service due to a company policy and brought the horse inside the eatery.
The horse "ended up doing his business on the floor," police said in a release.
The sight and smell of the horse's business "caused obvious distress and upset to customers trying to eat, as well as staff members," the release said.
The woman was issued a fixed penalty notice for causing alarm and distress to customers and workers at the restaurant.