Here are some advantages and disadvantages of dog harnesses vs. herm sprenger prong collars for your consideration. Which is preferable, a dog harness or a collar? Whether you're teaching a brand-new puppy or taking your dog for energizing walks, you'll need to make a decision, and there are many factors to take into account. Does a harness make training more effective? Is a collar more practical for quick walks? We have the inside scoop on the argument over harness vs. collar and what factors you should take into account before purchasing either one.