Depressed Dog

How about you play with him, with some toys or tricks. Sometimes bring him out for exercise, and maybe let him play with other dogs in your neighborhood? Well, I only have one dog at home, and she is used to play with us, and sometimes we bring her for a walk and play with other dogs for awhile too. I think dogs like to play with human beings too, just spend a little more time with him at this moment, pat him and make him feel comfortable, it may help him become better.