In January 2007, the Mayor of the city of Saskatoon (Canada) Don Atchison expressed a desire to see a mounted police patrol (= officers on horseback), saying it would be beneficial and a great public relations move.
First, "In any city where I've seen a horse patrol, people have been drawn to the animals. You never see them running away," said Atchison.
Second, positioning officers at such a height above large crowds improves their safety and gives them a clear view of what's going on. The horse can go where a patrol car can't and can move faster than an officer on foot.
So, once more we see the PR move to present one's image as animal-friendly. Wish to make the public feel good towards you? Present yourself connected to an animal.