"Will This Fit My Dog?" Or, "Which Size Should I Get?" We get these questions all the time and the best answer is "there's no way for us to know without having your dog in front of us." Plus, you may have a different opinion on what fits better. Using the measurements listed and measuring your dog is the next best way. Or, buy a range of sizes, try them all on and return what doesn't fit for free. See our Ready Returns program for details.