Dogs trained using methods involving punishment may have higher stress levels compared to dogs trained with reward-based methods, a new study suggests.
Researchers observed the behaviour of 92 companion dogs from seven dog training schools in Portugal.
The schools employed either aversive methods – which use mainly aversive stimuli, reward methods – which focus on rewarding desired behaviours, and mixed methods – which use a combination of both.
They filmed training sessions and tested saliva samples for the stress-related hormone cortisol.
According to the study, dogs trained using aversive and mixed methods displayed more stress-related behaviours, including crouching and yelping.
The animals trained using these methods also showed greater increases in cortisol levels after training, than dogs trained with rewards.
Punishment included things like turning the back to the dog as soon as they jumped or started to mouth, and stopping to walk if the dog was pulling on the leash.
Writing in the Plos One journal, the authors said: “This is the first large scale study of companion dogs in a real training setting, using the types of training methods typically applied in dog training schools and data collected by the research team.
“The results suggest that the use of aversive training methods, especially in high proportions, should be avoided because of their negative impact on dog welfare.”
To measure the dogs’ underlying emotional state, the researchers also conducted a cognitive bias test in an unfamiliar location outside of the dog’s usual training environment with 79 of the dogs.
Ana Catarina Vieira de Castro from the University of Porto, Portugal, and colleagues found that dogs from schools using aversive methods responded more pessimistically to ambiguous situations compared with dogs receiving mixed-or reward-based training.
The researchers say previous survey-based studies and anecdotal evidence has suggested that punishment-based training techniques may reduce animal welfare.
The authors add this study is the first systematic investigation of how different training methods influence welfare both during training and in other contexts.
They conclude: “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.”
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