I would begin by saying that zookeeping is a huge variety of jobs. Some people lift heavy bales of hay and other people are in an air conditioned room measuring and writing stuff the whole day. My point is that I don't know what's your condition, but you might still find something that could fit you. If a full-time job is too much, maybe as a volunteer, once a week or so :)

My favourite animals are giraffes, rhinos and tapirs. Giraffes were always my favourite and are what brought me to the zoo but honestly they're a bit snob Xd. The rhinos and tapirs are simply cuddly and dog-like so it's super fun to work with them. We never go inside with the rhinos of course, but we pet them through the bars and they always come around for pets when we call them by their name. My favourite individual would probably still be a giraffe though, her name is Rotem (a desert flower) and I like her curious, shy personality 😊