I'm kinda curious what other horses you'd have in the streets, there?
I've lived in the UK, and now Finland, and generally the only time I see horses are when ridden by the police.
(In Scotland it was common-place to see mounted police outside Rugby and Football matches, apparently the increased height gave them good visibilty. I'm sure they trained and selected for even-tempered horses, but I always imagined the combination of thousands of shouting pedestrians and horses was a bad one. If a horse got spooked things would end pretty badly, and quickly.)