That happens more frequently than you might think. My mother-in-law (a great lady) volunteered as a doson at the Cheyenne Mtn. Zoo in Colorado Springs, CO. She was always alert to this when she was escorting a group in close proximity to the tigers or lions. Warning visitors to be watchful ... as it wasn't a pleasant experience to be marked by one of the big cats.
Sure a lot of hill climbing at that zoo! Plus, at that altitude it seems like the elevations are in miles.