The horse has been controversial for years

The use of horses in town began to be controversial more than a century ago, but it’s not for the same reason calèches are being phased out now. Now it’s concern for animal welfare, but then, as the historian in this story mentions, it was the noise and smell of horses and the potential for the animals to transmit disease. (Horse poo can be a vector for tetanus. I don’t know whether horses involve other medical risks – the story doesn’t specify.)