One of the easiest training lessons you will ever encounter is halter
training. Why is this? It is because your dog already knows the basics of how to
function on a collar and leash system and walking is within their natural range
of movement. Thus, you are not asking the dog to do anything outside of its
normal field of activity. All you are doing is putting an extension on the
collar and leash, which allows for more control of the animal.
So to begin the discussion, what is a halter? A halter in its simplest of forms is no more than an extended collar which has a secondary collar that encircles the animal's upper torso just behind the front legs. There is a D-loop on the back for the attachment of a leash and the whole attachment usually buckles in the front. The halter is useful in stopping disagreeable behaviors and provides more control for the handler without wrenching the animal's neck to achieve this goal.
To halter train your dog, you must first get your dog used to the apparatus. Let them explore it, sniff it and generally just look it over and become comfortable with it. This will put the dog at ease that this is not some new form of torture that you have devised and the dog will be more willing not to resist in the next step of training, which is placing the halter on the dog.
Most often halters are placed on the dog by slipping the collar portion over the head and then wrapping the torso section around the dog just behind the front legs. Many systems use a metal buckle or even a plastic snap connector of the type common amongst backpackers which joins the pieces together thus forming two loops, one around the neck and the other around the torso, with a connecting piece in between. The D-loop would then be positioned on the dogs back so affixing a leash is no major task. There are variations on this system however so read the manufacturers instructions on your particular model so as to avoid injury to yourself or your pet.
Now that we have the halter on your pet, the hard part is over. Now you get to have some fun praising your pet for cooperating so well and rewarding them. Also give them a few minutes to explore the new sensation of the halter without the leash while rewarding them for not trying to remove it. The rewards will help with the next part of the training as well, which is getting them to walk while on a halter and leash system. My favorite method for this is to find an assistant who can walk a few feet in front of the animal and myself and offer some kind of treat to the dog, be it food or a favorite toy.
The dog quickly learns that the harness is not restrictive and will follow
the treats. Walk with your pet and allow them to sense that this device is not
an encroachment on their freedom. If the dog begins to pull you along, say no
and stand in one place just as in leash training. This will teach the dog that,
while the halter does not impede their normal movements, there are limits to
what they are allowed. In no time at all, you should have a pet that will
happily be haltered and be ready to walk at your side rather than pulling you
along over hill and vale.
The halter also has the added advantage of being a good handle should you need more control of a situation such as when aggressive behaviors are displayed. There is a simple technique to deal with this and avoid injuries to your pet or yourself. If you encounter a situation where you think aggression may be an issue quickly take in all slack on the leash and grab the harness between the collar and the torso loop. By pulling back on this section, you will raise your dog's front legs off the ground and distract them from their aggressive behavior. In smaller dogs, it is possible to lift the dog completely free of danger in this manner.