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

There is a growing number of dogs kept as companion animals, and the methods by which they are trained range broadly from those using mostly positive punishment and negative reinforcement (aversive-based methods) to those using primarily positive reinforcement (reward-based methods). Although the use of aversive-based methods has been strongly criticized for negatively affecting dog welfare, these claims do not find support in solid scientific evidence. Previous research on the subject lacks companion dog-focused research, investigation of the entire range of aversive-based techniques (beyond shock-collars), objective measures of welfare, and long-term welfare studies. The aim of the present study was to perform a comprehensive evaluation of the short- and long-term effects of aversive- and reward-based training methods on companion dog welfare. Ninety-two companion dogs were recruited from three reward-based (Group Reward, n=42) and four aversive-based (Group Aversive, n=50) dog training schools. For the short-term welfare assessment, dogs were video recorded for three training sessions and six saliva samples were collected, three at home (baseline levels) and three after the training sessions (post-training levels). Video recordings were then 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 the long-term welfare assessment, dogs performed a cognitive bias task. Dogs from Group Aversive displayed more stress-related behaviors, spent more time in tense and low behavioral states and more time panting during the training sessions, showed higher elevations in cortisol levels after training and were more ‘pessimistic’ in the cognitive bias task than dogs from Group Reward. These findings indicate that the use of aversive-based methods compromises the welfare of companion dogs in both the short- and the long-term.

to behave in a manner appropriate for human households. This includes, for example, learning to 49 eliminate outdoors or walk calmly on a lead [1,2]. The fact that dog behavior problems are the 50 most frequently cited reason for rehoming or relinquishment of dogs to shelters and for euthanasia

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[2] suggests that such training is often missing or unsuccessful. 173 To obtain physiological data on stress during training, six saliva samples were collected 174 per dog to allow assay of salivary cortisol [8,22]. Three samples were collected 20 min after each 175 training session (PT -post-training samples) and three were collected at home on days when no 8 176 training took place, approximately at the same time as PT samples (BL -baseline samples).

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Owners were asked not to give their dog water in the 20 minutes preceding each sample collection,

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The position of the 'positive' and 'negative' locations was counterbalanced across 244 subjects and training schools, such that for half of the dogs from each training school, the 245 'positive' location was on the right hand side as they faced the test area, and for the other half it 246 was on the left. Initially, each dog received two consecutive 'positive' trials (bowl placed in the 247 'positive' location) followed by two 'negative' trials (bowl placed in the 'negative' location).

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Subsequently, 'positive' and 'negative' trials were presented in a pseudorandom order, with no 249 more than two trials of the same type being presented consecutively.

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All dogs received a minimum of 15 training trials to learn the discrimination between 251 bowl locations. Dogs were considered to have learnt an association between bowl location and 252 food (the learning criterion) when, after a minimum of 15 trials, the longest latency to reach the 253 'positive' location was shorter than any of the latencies to reach the 'negative' location for the 11 254 preceding three 'positive' trials and the preceding three 'negative' trials. Each trial lasted a 255 maximum of 20 seconds. If the dog did not reach the bowl by that time, the trial automatically 256 ended and a latency of 20 seconds was recorded.

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All but two dogs were able to complete the training phase. For the two dogs that failed to 258 complete training, one did not show any interest in the food reward and the other was food-259 motivated but could not focus on the task. These two dogs belonged to Group Aversive.

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Therefore, the total number of subjects completing Phase 2 in Group Aversive was 42.

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-A Mann-Whitney test was used to compare the number of training classes attended 386 by the dogs before moving to Phase 2, to verify if these did not differ between groups.

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-A t-test for independent samples was used to compare the number of trials needed to 388 reach the learning criterion in the cognitive bias task between Group Reward and 389 Group Aversive, in order to explore whether the groups differed in learning speed.

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-A Wilcoxon signed-rank test was used to compare, in the cognitive bias task, the   behaviors. Fear-related elimination was never displayed during this study (Figure 2).   Figure 3).

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The display of avoidance behaviors such as body turn, move away, crouch and lying on side/back, 603 specifically in response to training techniques, highlights the aversive nature of the training 604 sessions at the aversive-based schools. Notably, lying on side/back was only displayed in 605 aversive-based schools (and mostly in School A, the school employing the highest frequency of 606 aversive stimuli). Finally, no differences were found between groups for body shake, scratch and 607 whine. Previous studies on dog training methods have also failed to identify significant 608 differences regarding these behaviors [8,9], suggesting that these behaviors may not be reliable 609 indicators of stress, at least in the context of training. In support of this view, whining has also Table S1a. Characterization of the training schools by types of behaviors trained, training sites 847 and class structure.
848 Table S1b. Definition of the aversive-based operant conditioning procedures used to classify the 849 dog training schools as aversive-based or reward-based. The schools were classified as aversive-850 based if they used some sort of positive punishment and/or negative reinforcement and as reward-851 based if they did not use any of these techniques. 2 months (inclusive); 2 -2.5 months (inclusive); 2.5 -3 months (inclusive); 3 -4 months 876 (inclusive); 4 -5 months (inclusive); more than 5 months, don't know]. Kruskal-Wallis and