It's so super double dog dare top secret that I needed that encrypted! (bgr.com)
These foods are primarily vegetable based and are not as digestible, usually doubling your dog's stool output. (pets.georgetown.org)
Vaun Duffy Double Dog Leash Coupler with Two Padded Handles - No Tangle Splitter Swivel, Reflective Stitching, 1 Inch Wide and Adjustable 18 - 24 Inches - Strong Lead for Walking 2 Large or Medium dogs (amazon.com)