Study reveals the best way to train your dog

A new puppy is a joy. But they are also a massive commitment. Without serious training, your pooch can end up behaving badly — leaving both you and your furry friend stressed and anxious.

But like raising kids, pet owners can struggle to work out how best to train their dogs, which, indeed, can act like small children in many ways.

For many, it comes down to a fundamental question: Do you reward your dog when it displays good behavior in an attempt to reinforce what is "good," or do you punish it when it does something wrong to teach it a lesson?

A new study published in the journal PLOS ONE may have the answer: The best way to train your dog appears to be with positive reinforcement for one crucial reason.

Here's how they did it — The researchers studied 92 dogs in seven different dog training schools in Portugal. The scientists observed three different training techniques depending on the school:

• Aversive — punishing bad behavior.
• Reward-based — reinforcing good behavior with treats.
• Mixed — a combination of aversive and reward-based.

The researchers filmed the training sessions and observed whether the dogs exhibited common stress-related behaviors, including body shaking, lip licking, yawning, crouching, and turning away from the trainer.

They also measured levels of the stress hormone — cortisol — in the dogs' saliva to see how their bodies reacted to punishing behavior, which in this study included jerking the dog's leash, using electric collars, or trainers leaning toward the dog in a threatening way.

Finally, the researchers conducted a nifty experiment called a 'cognitive bias task,' which involved placing bowls — some empty, some filled with food — to gauge the dog's emotional or "affective" state.

Ana Catarina Vieira de Castro, lead author on the study, tells Inverse this task looks at how the dogs respond to "ambiguous situations."

Essentially, the researchers taught dogs to expect bowls placed in certain spots to contain food or to be empty. They then placed the bowls in more "ambiguous" positions to see how dogs reacted after a stressful training session.

By testing the dogs in this manner, they could determine the dog was in a more pessimistic ("glass half empty") or optimistic ("glass half full") mood, Viera de Castro says.

"Dogs in a more positive affective state 'see the glass as half full,' and run towards the ambiguous bowls as if they held food treats; whereas dogs in more negative mental states 'see the glass as half empty' and move more slowly towards these bowls, unconvinced that they will find a food treat," Viera de Castro explains.

What they discovered — The dogs which had undergone aversive training methods exhibited greater stress-related behaviors, such as panting or yawning, for example, than did dogs which received rewards. These behavioral differences were clear both during and after the training sessions, the researchers found.

Dogs which had undergone aversive training also showed higher levels of the stress hormone, cortisol, in their saliva than dogs in the reward group. Overall, dogs in the aversive group had reduced emotional welfare compared to the dogs in the reward training group, the researchers reported.

"Drawing on our findings, relying purely on reward-based methods would be the best approach if we aim at the least impact possible on dog welfare," Viera de Castro says.

Why it matters — The study's findings are in line with previous research which showed dogs which wore electroshock collars for training purposes had reduced welfare. Indeed, the evidence against electroshock collars has prompted certain countries to place bans on such collars.

Where this study differs from past research is that it finds the level or proportion of punitive measures matters, too. The more punitive the training regime, the more stressed the dogs will become, the data suggest.

Things got more complicated when comparing the mixed training style to the aversive training group, however.

Digging into the details — The researchers did not find significant differences in cortisol levels between the dogs in the aversive group and dogs which received a combination of aversive and reward-based training.

Both sets of dogs displayed similar levels of stress-related behaviors, too.

"This most likely means that, although dogs from Group Aversive experienced more stress than dogs from Group Mixed during training sessions, this difference was probably not that meaningful," Vieira de Castro says.

What we don't know — The study has some important limitations, but chief among them is that this is not a randomized control trial. Doing such a study would have serious ethical implications, however, especially as some countries have already banned training techniques like shock collars.

The researchers relied instead on volunteers who had already signed their dogs up to participate in the training schools. This means the dog breed and attitudes of the dog owners were both beyond the researchers' control. It is possible different breeds react differently to certain training regimens.

Moreover, some studies suggest dogs which received aversive training did not experience significant negative effects.

The big idea — Ultimately, the study shows why owners have to take into consideration both their pet's welfare and how well the different training techniques actually work. Depending on the pooch, a small amount of stress as a result of using a mix of aversive and positive training techniques may be a necessary trade-off for some dog owners.

"As we could not find long-lasting effects of mixed methods on dog welfare, there appears to be a room for the use of some aversive stimuli in training without comprising dog welfare in the long run," Vieira de Castro says.

"The choice of the training method should not be based only on its effects on animal welfare," she says.

"Dog training is a purpose-built tool and, hence, its efficacy should also be considered in the equation. At present, we still do not know which methods are more effective."

Vieira de Castro and her team hope their study can be helpful in developing further recommendations for dog training.

"To develop recommendations and guidelines for dog training, it is relevant to combine what we currently know about the effects on dog welfare with research in the efficacy aspect of dog training methods," she says.

Abstract: Dog training methods range broadly from those using mostly positive punishment and negative reinforcement (aversive-based) to those using primarily positive reinforcement(reward-based). Although aversive-based training has been strongly criticized for negatively affecting dog welfare, there is no comprehensive research focusing on companion dogs and mainstream techniques, and most studies rely on owner-reported assessment of training methods and dog behavior. The aim of the present study was to evaluate the effects of aversive and reward-based training methods on companion dog welfare within and outside the training context. Ninety-two companion dogs were recruited from three reward-based schools (GroupReward,n = 42), and from four aversive-based schools, two using low proportions of aversive-based methods (GroupMixed,n = 22) and two using high proportions of aversive-based methods (GroupAversive,n = 28). For evaluating welfare during training, dogs were video recorded for three sessions and six saliva samples were collected, three at home (baseline levels)and three after training(post-training levels). Video recordings were used to examine the frequency of stress-related behaviors (e.g.,lip lick, yawn)and the overall behavioral state of the dog (e.g., tense, relaxed), and saliva samples were analyzed for cortisol concentration. For evaluating welfare outside the training context, dogs participated in a cognitive bias task.Results showed that dogs from Group Aversive displayed more stress-related behaviors, were more frequently in tense and low behavioral states and panted more during training, and exhibited higher post-training increases in cortisol levels than dogs from Group Reward. Additionally, dogs from Group Aversive were more ‘pessimistic’ in the cognitive bias task than dogs from Group Reward. Dogs from Group Mixed displayed more stress-related behaviors, were more frequently in tense states and panted more during training than dogs from Group Reward. Finally, although Groups Mixed and Aversive did not differ in their performance in the cognitive bias task nor in cortisol levels, the former displayed more stress-related behaviors and was more frequently in tense and low behavioral states. These findings indicate that aversive-based training methods, especially if used in high proportions, compromise the welfare of companion dogs both within and outside the training context.