Recently there has been a real push to use flat harnesses in training loose leash walking. Many people wonder why since harness are typically seen as causing pulling.
1. First, the harness itself does not cause pulling, it is the two of you pulling against each other that does.
Wearing a leash is unnatural for dogs as it is for humans. A dog must learn that is more rewarding to stay near a person and move with him than exploring on his own. That takes patience and careful attention to the distraction level on the person's part and liberal use of reinforcers (food, toys, attention, real life reinforcers etc.) It's worth taking the time to train it without using a leash first.
A well fit flat harness allows the dog to move normally and freely. It is used only as a device to keep the dog safe, like a seat belt, rather than as a training tool. If a dog does stop short, the pressure of the straps is spread over a wide area (rather than concentrated on a narrow strip on the neck) and all areas have either muscle or bone that protect the organs so injury is much less likely.
Unfortunately, all 'no-pull' harnesses can injure the dog in different ways depending on the their design. Those that are not long enough chaff the dog's skin typically behind the front legs, others tighten around the chest with leash pressure, still others sit across the shoulders to limit proper motion or tighten across the chest to change the dog's gait. All of these can cause health issues on a dog and are punitive in nature. Dr. Chris Zinc, an expert in dog sport mechanics, has done research on this. "In a limited gait analysis study, Dr. Zink observed that dogs wearing no-pull, front clip harnesses bore less weight on their front legs than they normally would – even when the harness wasn’t attached to a leash! In addition, the dogs bore less weight on the leg that was on the far side of where the person walked, even when there was no leash attached; when the dog had a leash attached, it was more significant. This suggests to her that the dog was reacting to the presence of the harness against the leg by pushing harder against it. In all cases, the gait of the front limbs was altered whenever the harness was on." Whole Dog Journal July, 2013
The best harnesses allow the dog to move freely. They have a Y joint that should fit over the breast bone. They have a chest ring or back ring or ideally, both. This gives you the option of clipping the leash to either or both locations at the same time to provide the dog with more information. Two that I have had success with are the Balance harness and the perfect Fit Harness. The Perfect Fit is a padded version that fits long bodies and protects short-haired dogs or dogs with thin skin. (I am not affilated with nor do I sell either harness.)
2. The second and main reason for not using a collar (flat collar, rolled collar, choke chain, limited slip, prong, Martingdale etc) is that they may cause many unwanted health effects on a dog.
The neck area where a collar sits on a dog is a very important region of the body. There are glands, lymph nodes, blood vessels, nerves, trachea, and more. All of them are exposed and not outwardly protected by bone, muscle or fat. Any pressure on the neck whether from sudden sharp jerks or even gentle ongoing pulling can negatively impact these areas. Other unwanted impacts include misaligned spine (from being pulled to one side) and long-term structural issues. Andres Hallgren of Sweden in a study found that 252 dogs had mis-aligned spines, and 65% of those had behavior problems. In addition, 78% of the dogs labeled hyperactive or aggressive had spine issues. The dogs in the study were volunteered by their owners and considered well cared for (not abused dogs). Source: Paul Owens "The Dog Whisperer: A Compassionate, Nonviolent Approach to Dog Training")
Have a look at the brochure showing the biology of a dog's neck created by Els Vidts FreeDogz.com. Potential Collar Damage brochure It shows the potential health impacts on a dog from being pulled on a collar. Els is a student of Turid Rugaas.
Where Did the Idea for Using Collars Come From?
If we look historically at why dogs wear collars, it probably seemed like the best way to control them. A thin rope tied around the neck was a quick and easy. Unfortunately, that was looking at the tool from the human side of the leash and didn't consider the best interests of the health of the dog. It's time to ask questions and change our choices in the present! Collars today, now that we know better, should be used only for tags.
I personally have had three dogs that we know were adversely affected by wearing flat collars attached to a leash. One ended up with spondylosis in his neck which caused a very painful pinched nerve (took 30 days to heal and stop his screaming in pain when he moved his neck awake or asleep despite pain medication). He also had trouble manipulating his tongue to eat and we ended up euthanizing him since he lost so much weight. He was 13yo and otherwise in prime health. My current dog Jessie adopted as a 7mo pup coughed and gagged when any small amount of pressure was applied to her neck (trachea damage). We immediately switched to a flat walking harness. Once in a while, she still gags when the harness is not sitting correctly and she gets pulled. Her early damage was permanent. The third had a collar attached to a long line while the owners rode their horse. Her spine was out of alignment. I have had several clients as well who have had health issues with dogs that were walked only on a collar. These are not isolated events and combined, do suggest we should re-examine if collars are the best choice for dogs when walking on a leash.
Note: the harnesses talked about here are not service dog harnesses. They are flat walking harnesses for everyday use. They may be worn underneath a service dog vest or alone. Stiff mobility and bracing harnesses and other related harnesses need to be fitted correctly to prevent unwanted wear and tear on your service dog's body. Height of handle, stiffness of the harness and other features are important to minimize structural stress on your service dog.
If you would like to learn how to teach your dog to walk on a loose leash, have a look at my classes listed in the catalogue. My harnesses classes are for dogs who dislike wearing them or who pull hard in times of high excitement. Classes start the first wed of each month.