TheTractive GPS trackingdevice for pets lets you track your dog live , similar to the Tagg pet tracker and comes with gps dog fence options so you are alerted when your dog leaves certain zones. The Tractive GPS pet tracker also guarantees to be waterproof while Tagg the pet tracker GPS locator for dogs is also an activity tracker that can help keep your dog healthy. Both GPS alert you when your dog leaves a set area or help you find lost dogs back. The Marco Polo pet locator on the other hand is great for finding your lost dog especially in remote areas where there’s no cell phone coverage. The Marco Polo lost pet finder however doesn’t allow real time tracking , while TractiveGPS collarfor dogs and the Tagg tracker dog tracking system do have live and real time dog tracking . If you want a waterproof dog collar GPS that allows real time tracking with a smartphone app, then the Tractive gps pet tracker is right for you. If you’re not sure if this is right for your dog, check out other GPS for dogs.