Gentle Leader, from PetSafe, makes walking aids for dogs that pull. The Gentle Leader Head Collar steers from the nose, the way a halter leads a horse, and the Easy Walk Harness clips at the chest so that pulling turns the dog to the side.
Both are sized by the dog, so check the size chart. A head collar takes a few short sessions for a dog to accept and should never be used with a long line or sharp jerks on the lead.
