1. Youtube videos for dogs to watch.
2. Try to teach your dog a language of barks
3. Sew two dog beds on top of each other with a little hole to get in side. This will be nice for chihuahuas because they like to burrow inside things.
4. Dog GPS tracker. Watch the movements of all the dogs in the city on a dog tracker website.
5. Stray dog newspaper delivery to hobos.