This is an idea I got from RonE on another thread. The ideas below are RoneE's. What can you add to the list?
Dogs bark. They bark more when they're bored or scared or lonesome.
Dogs pee and poop wherever they feel like it until they learn the advantages of doing it where you want them to.
Dogs have medical emergencies, normally when your vet is closed.
Dogs are not solitary animals. (Hamsters are.)
When you buy a puppy from Petland, you are not "rescuing" it. You are lining the pockets of the Puppy Mills and encouraging them to continue.
Impulse buying from a Back Yard Breeder is a chance to get a dog that is not healthy (disease, genetics, temperment or all of these) and keeps people breeding dogs for money in business.
Dogs need exercise (like a walk off the property for an hour and a half a day.. regardless of weather).
Dogs need training. Includes Puppy or beginner obedience classes and homework.
Dogs need socialization and training in different locations so they are used to people, kids, and other things like other dogs, bikes, shopping carts etc.
Dogs are not supposed to be aggressive/protective with their food, toys or any other thing.