[header] How to stop a dog from pulling on its leash [title] Use a proper collar. [step] Be sure that your dog has a comfortable collar that fits it properly. The collar shouldn't be so tight that it is choking the dog, but should be tight enough so that it does not slide up and down the dog's neck. 
[substeps] You should be able to slide your hand between the dog's neck and collar when it is secured in place. Many people choose to use a harness instead of a collar.