BS”D
Here is what Rav Ovadia Yosef has to say about zoos:
Visiting a Zoo
Personally, I try to go once a year to a zoo. I forgot to go this past year; I’ll try to spend a day in Vienna the next time I fly abroad so that I can see the panda there. Then I get a double header – shekacha loi for the panda and meshane habriyois (followed by Dayan HaEmes if I actually get my hands on him) for Moshe Aryeh Friedman!