A head collar is a type of harness that goes around a dog's head like a muzzle. It helps to control the dog's movements and can prevent them from pulling on the leash. Full definition
You must prepare and train for this before you and your pooch are able to a dog head collar on a daily basis. (topdogtips.com)
For the average dog guardian, use of head collars such as gentle leaders and training the dog to maintain eye contact with their human are good ways to start, she said. (baywoof.com)
Use head collars in the clinic to prevent dogs from pulling on leash and jumping on the staff. (animalbehavior.net)