The inventive subject matter provides a device in which a pet stroller comprises at least three wheels, a battery, a motor, and a treadmill. The treadmill is positioned inside of the stroller and has a belt upon which an animal walk and run. The battery is configured to power the motor, and in at least some contemplated embodiments, movement of one or more of the wheels of the stroller can be used to directly move the belt of the treadmill, and/or indirectly power the belt by providing power to the battery.