A harness will give you 100% control of your chihuahua. A simple collar with a leash attached should be enough for well-behaved dogs. However, for wild ones, the naughty troublemaker chihuahuas – we strongly suggest getting a harness. You’ll avoid their neck getting hurt from pulling, and the harness divides the tension all over the dog’s body. Also, a harness discourages pulling at all, while making the dog comfortable.