First, if the dog is not used to a harness, he/she will not take kindly to having the organizer on his/her back. If using on a dog four (4) straps are highly recommended. Two (2) straps connected to the organizer panels draped over the back of the dog, one (1) strap for his/her chest (to keep the organizer from sliding off when the dog sits) and one (1) for his/her under belly for stabilization. Keep in mind, the length of the additional straps depends on the size of your dog. We sell 18” and 24” straps.