The website globalspecies.org offers a comprehensive information menu. Under LISTS is located institutions, zoos, etc. This list includes worldwide facilities and their collection inventories. However, the inventories are not dated except at bottom of each page the company and 2017.
It is far outdated- from when the International Species Information System was public, I think that stopped around 2010, but I'm not sure.
This site seems to have been pretty much shutdown. Anybody know what happened? While its lists of species per ecoregion may have been incomplete and out of date, they were still the only ones available, at least that I could ever find.