Sometimes they all behave like dogs, with barking and tail wagging, and sometimes they are more human. But all other animals and birds are animals and birds, including references to pets.
However I do like little touches like them all having the kind of names a pet dog would have.
I dunno - they’ve never met another type of animal that talks, they frequently see birds that are just birds, the dogs have regular jobs, they meet dogs from other countries, and the sports world is comprised of only dogs. They also see koalas, fruit bats and other Aussie-type animals that aren’t anthropomorphic. There’s an episode where they make up a talking horse, and everyone seems to react to it like it’s super weird that a horse would talk.