Asked by: Thomas Galea, by email
It’s not obvious what ‘intelligence’ means when comparing different species. Dogs evolved from social creatures, and have a longer and closer association with humans, so it’s generally easier to train and communicate with them.
But, cats have evolved specialist hunting and reasoning skills that dogs lack. Brain size is no help, otherwise whales would be vastly cleverer than humans. So, there’s no sensible answer to your question, I’m afraid.