I had a dog myself who used harness. I recommendo 100% collar. Why? because he will fear of the harness if you take him outside even for a walk and if you leave him with the harness on he will start chewing it and at last breaking it. Collars are much better because you can leave it on your dog at any time and if you want to give your dog a walk you can just pick a leash and adjust it to the collar. And the best thing is that collar come in a variety of textures and colors!!