Neither knows how to talk on the telephone. Neither understands what you see in cats. Dogs are very direct about wanting to go out. Dogs don't feel threatened by your intelligence. You can train a dog.
Dogs are easy to buy for.
You are never suspicious of your dog's dreams. The worst social disease you can get from dogs is fleas. Dogs understand what no means. Dogs understand if some of their friends cannot come inside. Middle-aged dogs don't feel the need to abandon you for a younger owner.