The study was made up of 63 dogs that were identified as having poor recall skills and related problems, such as attacking livestock, a main reason for the shock collar's use in the U.K. The canine subjects were divided into three groups: Group A used a shock collar under the direction of trainers nominated by the Electronic Collar Manufacturers Association (ECMA). Groups B and C trained without a shock collar. One group under the direction of the same ECMA trainers and the other with trainers from the Association of Pet Dog Trainers, a group committed to reinforcement based methods.
The trainers worked with each dog for two 15-minute sessions a day, for five days. The interactions were videotaped to analyze behavior, and saliva and urine samples were collected to measure cortisol levels (a hormone associated with stress).
The researchers found that the dogs in the shock collar group showed significantly more stress behaviors, such as tense body language, yawning, and disengaging with the environment. Although a smaller preliminary study found higher cortisol levels associated with the shock collar, there wasn't a significant difference in cortisol levels in the larger research.
Furthermore, following the five days of training, 92 percent of owners reported improvements in their dog's behavior. There was no significant difference in reported efficacy across the three groups.
Some people say that there are certain behaviors, like a reliable recall, that can't be taught without a shock collar. And that is simply not true. I've seen people train rock solid recalls using only reinforcement based methods. It's nice to have this scientific research to back up that claim. I was also impressed that the U.K. government commissioned this research to inform their policy.
Of course training using reinforcement based methods doesn't come without dedication. Unfortunately there are no shortcuts in dog training! However, a key learning from this study is around the consistency in results across groups (as a side note, while results seemed consistent in the short term, I believe that punishment tools, like shock collars, can often develop unintended consequences in the long term). The short training sessions repeated every day was the primary diver for getting results. Even if you only train for five minutes a day, if you stick to it, you'll see progress in your training challenges.