Both are suspicious of the postman. Neither understands what you see in cats. Where Dogs Fall Down Men only have two feet that track in mud. Men can buy you presents. Men don't have to play with every man they see when you take them around the block.
Men are a little bit more subtle.
Men open their own cans. Dogs have dog breath all the time. Men can do math stuff. Holiday Inns accept men. Men are strong and like to lift things to prove it.