Does training method matter? Evidence for the negative impact of aversive-based methods on companion dog welfare

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 (Group Reward, n = 42), and from four aversive-based schools, two using low proportions of aversive-based methods (Group Mixed, n = 22) and two using high proportions of aversive-based methods (Group Aversive, 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.

Dogs are more pessimistic if their owners use two or more aversive training methods

“…This may reflect a negatively biased processing of ambiguous information, as is found in depressed people 29 , 30 rats exposed to chronic psychosocial stress 31 , and in a variety of other judgement bias studies involving animals in putative negative affective states 25 , 26 . The results support the findings of Vieira de Castro et al 28 , suggesting that the use of aversive dog training methods may induce longer-term negative mood states and hence poorer welfare compared to training methods that do not involve aversion.…”

“…For example, application of a punisher poorly contingent with the behaviour of the dog is likely to be more stressful for the animal than where it is appropriately applied 12 . Nevertheless, our findings appear to replicate those of Vieira de Castro et al 28 , where categorization of groups was conducted based on attendance to different training classes, with methods of training further categorized through video analysis of sessions.…”

“…Matching pairs of dogs by these criteria in this study enabled us to conclude with greater confidence that methods used in training rather than demographic variables were associated with mood state, and hence welfare, in dogs. The strength of this study design adds weight to the previous findings of Vieira de Castro et al 28 . Further research to investigate the extent to which cognitive biases do or do not vary with factors such as breed, individual personality, learning or stress coping style of dogs or owner based factors such as attitude or lifestyle would be valuable, allowing future studies to better control for any confounding factors and also to be less constrained in case recruitment for those characteristics found to be unrelated to judgement biases.…”

“…Given that mood is hypothesized to be influenced by experience of reward and aversion, this approach is appropriate to evaluate differences in affective state between dogs trained using rewarding or aversive stimuli. Previous research has investigated differences in cognitive indicators of affect and welfare between groups of dogs attending training classes where different approaches to training were used 28 . Dogs attending classes advocating mainly aversive training methods were found to be more ‘pessimistic’ in a cognitive bias task than dogs from training classes adopting a predominantly reward-based approach.…”

Improving dog training methods: Efficacy and efficiency of reward and mixed training methods

“…However, the scientific evidence for this has been limited as most studies lack objective welfare measures, investigation of the entire range of aversive techniques and companion dog-focused research [ 1 ]. Recently, in the first large-scale quasi-experimental study of companion dog training (n = 92), Vieira de Castro et al (2020) [ 2 ] found that dogs trained with aversive stimuli displayed more stress behaviors during training, showed higher elevations in cortisol levels after training and, if trained exclusively with aversive methods, were more ‘pessimistic’ in a cognitive bias task than dogs trained with either reward and mixed methods. These findings strongly suggest that using aversive stimuli in training compromises companion dog welfare both within and outside the training context.…”