I worked at a few zoos when I was younger and we took really good care of the animals and never did any harm to the animals.
All the people who worked at our zoos that I worked at really had a passion and love for animals including myself.
We took really good care of the animals and we never harmed any of the animals we had in the zoos.
I've heard of a few zoos who've harmed their animals but most zoos have people that work there that have a love and passion for caring for those animals.
So as long as you get good people working in the zoo then the animals should be treated just fine and not be harmed.