There are a lot of obstacles in the way of our understanding animal intelligence - not the least being that we can't even agree whether nonhuman species are conscious. We accept that chimps and dolphins experience awareness we like to think dogs and cats do. But what about mice and newts? What about a fly? Is anything going on there at all?
I would say that IQ is the strongest predictor of which field you can get into and hold a job in whether you can be an accountant lawyer or nurse for example.