My 2 y/o jack Russell seems very depressed. He doesn't want to go outside and I have to carry him out in the mornings and before bed to get him to go to the bathroom. He lays around all day and will only get excited if I take him for a walk. When I leave for work he crowds the door and doesn't want me to leave. Each day he gets more and more depressed. Other than nightly walks what else can I do to cheer him up. It breaks my heart to see him like this.