Where do you get the idea that dogs are the messy ones? Dogs may cause a mess here or there, but cats are the ones on the shelves knocking things off, cleaning their privates in public (like dogs), screwing anything they see, yes I've seen a cat try to screw a dog! Cats don't try to save your life where as dogs will do anything for their owners. Some cats may, but that depends on the cat. You can train a dog for such things like leading the blind. Cats are great friends. Both animals are very clean and both animals can bite. Dogs can smile. Cats can't smile. My friend's cat would scream for hours. That's no better. Male cats will spray stuff to own it unless you get their glands removed, dogs can be house trained to not piss on your furniture. You can't train a cat to piss or shit anywhere. You just have to make their litter box more interesting or put it where your cat wants it even if it's most inconvenient to you. Cats are unpredictable. Dogs want to please you. Both animals love affection. Dogs come in much more different packages that can suit everyone. Cats are all generally in the small to medium size. Larger dogs and stronger dogs can be rough housed with. Cats and small dogs need to be handled delicately. No fun for the tougher crowd. Dog can be trained not to bark, but they make much better intruder alarms than cats. You are safer with a dog than a cat. Cats bite and scratch people. Dogs bite. Larger dogs bite less often. Small dogs and cats bite or scratch more often (also depending on the personality of the individual dog or cat.
I raised three kittens. I respect cats, but I am by far a dog person...a big dog person. There's nothing like getting your face slobbered on by a loving dog that sees you as their best friend. They give you unconditional love. Cats give you that love if you give them something in return. Sure they love you, but they show it like a human would. Cats are more like people than dogs. Cats are independent and self sufficient. Dogs are like children that need you. Some people prefer the human type friendship with a give love get love type of relationship while others like the child that looks up to them for love, companionship, and attention.