Interesting mix. When I first moved to Tucson in mid 1990's the Arizona-Sonora Desert Museum had a mix of two black bears and two gray foxes. Now they only have one black bear in that exhibit (and a gray fox in Cat Canyon) and I am sure a mix like that would not happen these days.
@Arizona Docent Bears and foxes or bears and wolves in European zoos is a fairly common mix. I even saw a few foxes in with the Polar Bear/Brown Bear hybrid animal at Osnabruck Zoo in Germany. At that facility, and in Olderdissen and other zoos, there seems to always be a connected side exhibit that is accessible only by the canids. I even saw Brown Bears with American Black Bears at Pairi Daiza...a very rare mixed-species exhibit these days!