The Shocking Truth About Shock Collars
people who use shock collars may end up paying more on a dog trainer or behaviorist if use of the collar affects their relationship with the dog or the dog’s welfare. The application of shock may result in fear, aggression or learned helplessness. Poor timing on the part of the trainer will increase these risks.
“Despite the methodological concerns, it appears that aversive training methods have undesirable unintended outcomes and that using them puts dogs’ welfare at risk. In addition, there is no evidence to suggest that aversive training methods are more effective than reward-based training methods. At least 3 studies in this review suggest that the opposite might be true in both pets and working dogs. Because this appears to be the case, it is recommended that the dog training community embrace reward-based training and avoid, as much as possible, training methods that include aversion.”
"...there is no credible scientific evidence to justify e-collar use and the use of spray collars or electronic fences for dogs"
The use of electronic training collars poses risks to animal welfare.
When people use electronic shock collars, it is typically as positive punishment to punish a dog for an unwanted behavior. They are also sometimes used as negative reinforcement by applying the shock until the dog does the behavior that is wanted.
...there is no credible scientific evidence to justify e-collar use and the use of spray collars or electronic fences for dogs. On the contrary, there are many reasons to never use these devices. Better training options exist, with proven efficacy and low risk.
Studies show increased fear and stress in dogs trained with shock collars. And it is possible for dogs to associate this with things other than the behaviour being punished, for example with the trainer, the location of the training, or (in the case of boundary fences) with people or dogs who happen to be walking by.