If dogs rules the world planet of the apes style what is the first thing they'd do? And same for if cats did?

Dogs would corner the meat markets and crap wherever and whenever they pleased.

Cats would outlaw the flea bath and demand solid white albacore in water, not the cheap stuff. Then they would take a nap.

If dogs ruled the world, every corner would have a few fire hydrant, and everyone would drive a firetruck.

If cats ruled the world, it would be as it is now, because they already do, don't they?

Dogs and cats do not posses a complex intelligence the way primates do. So they main concerns would be basic instincts:to eat, drink and reproduce. No foreseeable taking over and ruling from cats and dogs soon!

Trade houses with people. The cats would banish people to their own houses.