Do aversive-based training methods actually compromise dog welfare?: A literature review

The methods by which dogs are trained vary between methods involving mainly negative reinforcement and positive punishment (aversive-based methods) and methods based essentially in positive reinforcement and negative punishment (reward-based methods). However, the use of aversive-based methods is highly controversial. While some people defend their merits, others are concerned with their potential negative effect on dog welfare. To date, some studies have been performed aiming to assess the effects of aversive- and reward-based methods on the welfare and behaviour of dogs. In the present paper we perform a comprehensive review of those studies with the aim of characterizing the state of the art of scientific knowledge of the topic. Generally, the published studies suggest that the use of aversive-based methods is correlated with indicators of compromised welfare in dogs, namely stress‐related behaviours during training, elevated cortisol levels and problematic behaviours such as fear and aggression. However, there are a number of limitations that prevent any strong conclusion from being drawn. First, a considerable proportion of the studies relied upon surveys rather than on objective measures. Second, they focused on sub-populations of police and laboratory dogs and, thus, only represent a small portion of dogs undergoing training. Finally, the empirical studies have concentrated mainly on the effects of shock-collar training, which is only one of several tools used in aversive-based training, and, in some studies, the description of the training methodologies lacks details. Here we present a description of the published studies, discuss their limitations, debate other aspects that, in parallel with the nature of the training methods, may affect dog welfare, and point to future directions for research on the topic.