The end for shock collars? These studies show it would be a good idea

Two new reports make a strong argument against the use of shock collars in dog training.

By Zazie Todd, PhD

Something puzzles me about the arguments made by shock collar advocates. On the one hand they claim the e-collar doesn’t hurt, and on the other they say it’s a last resort to prevent ‘dead dogs’ due to recall and chasing problems. Surely the second justification casts doubt on the first? Two new scientific studies funded by the UK’s DEFRA address both arguments, and conclude that e-collars are unnecessary and detrimental to animal welfare.

Shock collars (including invisible fences) are already banned in many countries because of welfare concerns. The DEFRA studies aimed to investigate the welfare of dogs trained using e-collars. The results will surely add to calls for shock collars to be banned in England and Scotland (they have been illegal in Wales since 2010), and elsewhere. 

Beautiful red border collie does a trick
Photo: Ksena Raykova/Shutterstock

The first study (Defra AW1402) included extensive pilot work, an investigation of the electrical resistance of wet and dry dogs (conclusion: wet dogs get zapped more), and a comparison of the features of several purchased shock collars. 

Only a handful of instruction manuals stated that vocalizations indicate the shock is too high. They did not explain all features well, particularly the warning tone or vibration which is meant to precede a shock (not all models had a warning tone). Most manuals suggested use of the continuous shock option that is stopped when the dog does the required behaviour, rather than a momentary stimulus (for quadrant enthusiasts, this is using the collar as negative reinforcement (R-) rather than positive punishment (P+)). One of the collars, bought over the internet, turned out to be a counterfeit with no cut-off for the continuous shock, and two of the genuine collars had faults.

The manuals assumed people were using the collars to teach general obedience, but some also mentioned particular problem behaviours. The scientists conducted a survey that found almost all dog owners who use shock collars use it for problem behaviours, particularly recall and/or chasing. Owners were not able to explain properly how they had used the collar in training. Particularly worrisome is that “some end-users either fail to read the instructions, misunderstand or deliberately disregard the advice in the manuals.” (p25)

Owners reported that 36% of the dogs vocalized (e.g. yelped) the first time the e-collar was used, and 26% of dogs vocalized on later use(s) of the e-collar. Six per cent of owners said they started at the highest shock level the first time they used the collar, and either stayed at this level or adjusted down from there. The scientists say that “some of the reported use was clearly inconsistent with advice in e-collar manuals and potentially a threat to the dog’s welfare.” (p25)

The scientists collected saliva and urine samples from the dogs that had been trained using e-collars and a matched sample that had not, plus an extra set of controls. The samples allowed them to check for physiological signs of stress at various points in data collection. They also did behavioural and training tests on the dogs, including to the fitting of a dummy (inactive) e-collar and having both owner and researcher conduct training sessions. 

They tested whether there were differences between when the dogs were not wearing the dummy collar compared to when they were were, with an extra control group of dogs who never wore the dummy collar.

In the e-collar-trained dogs, salivary cortisol increased significantly when they were wearing a collar, compared to dogs trained only using positive reinforcement. The researchers say this “suggests a negative association with anticipation of stimulus application.” (p28). The e-collar-trained dogs also had a significant increase in tense behaviour, compared to the other dogs. They were very attentive to their owner whilst wearing the collar, to the extent that the researchers could not do the training task with some of these dogs. During training, the control group (including those trained using positive reinforcement only) were significantly more attentive to their trainer than the e-collar dogs. 

The first study concluded that “for a subset of dogs tested, the previous use of e-collars in training are associated with behavioural and physiological responses that are consistent with significant negative emotional states; this was not seen to the same extent in the control population. It is therefore suggested that the use of e-collars in training pet dogs can lead to a negative impact on welfare, at least in a proportion of animals trained using this technique.” (p4).

"...dogs have learned that the presence of their owner (or his commands) announces reception of shocks"
Because so many owners used the shock collars in a way that was not consistent with the manuals, the second study (DEFRA1402DWa) was designed to investigate what happens when a shock collar is used according to the manufacturer’s instructions. This includes a warning cue prior to the shock, so that it can be cancelled if the dog responds to the warning, and checking the level of shock to use for each dog. The Electronic Collar Manufacturer’s Association assisted with the design of the training protocol, and suggested the trainers who used the e-collar, who were also experienced in using other methods of training such as rewards.

Three groups of dogs were tested, with 21 dogs in each group. All of the dogs were referred because the owner said they had problems with recall and chasing (e.g. of sheep, cars, bicycles). This issue was chosen because it is one for which those trainers who use shock collars often recommend them.

Group A were trained using e-collars by dog trainers who had completed industry training. Group B were trained by the same trainers, but not using any shock and using lots of positive reinforcement. Group C were trained by members of the UK’s APDT (Association of Pet Dog Trainers) using no shock and lots of positive reinforcement

The APDT (UK) has a code of conduct which states that “coercive or punitive techniques and/or equipment should not be used, recommended, advertised or sold by members” and this includes the shock collar which they describe as an “abusive device”. (N.B. APDTs in other countries have different policies).

Groups B and C were both control groups, as neither was trained using shock collars. The reason for two controls? Group B is a useful control because they are the same trainers as Group A, but they are not blind to the purposes of the study, so it is possible they could unintentionally affect the results. Also, since they usually rely on shock collars they may not be as experienced in using reward-based methods as the trainers in Group C, who never use shock collars. 

All of the dogs were evaluated on a number of standardized tests prior to the start of training, and the dogs in each group were closely matched. Of course, researchers can’t shock people’s dogs without their permission, so for Groups A and B the dog owners were allowed to express a preference. Only two owners did this, one wanting their dog to be in the shock collar group and one wanting it not to be. It’s to the credit of the experimenters that they did not just swap these two dogs; in fact each one was swapped with another well-matched dog, to ensure matching between the groups.

Each dog was trained over a period of five days, although occasionally the trainers declared training complete after four days. The training took place in a field with a livestock pen in it; although the field used for Group C was different than for Groups A and B, the set-up was closely matched. At the end of the training, owners were brought in to have the training explained to them, so that they could continue as necessary at home. All of the training sessions were video-recorded, and various other measures (such as salivary cortisol) were taken during and after the training.

Stills from the videos were assessed by reviewers who were blind to the aims of the study, and to which group the dogs were in. You are probably thinking it will have been obvious which dogs were in the shock group, as the collars are visible, but the researchers thought of that: they had some e-collars de-activated, so that dogs in all three groups wore a collar (and therefore looked the same), but only Group A had the active collar.

So as you can see the design of the study was very careful to make sure that any results would be due only to the method of training. The dogs also returned to the training centre for further tests and observations three months after the training period, to assess any longer-term effects.

When examining the results, the researchers had to combine variables (where appropriate) and adjust the statistics to take account of the fact that they were conducting a large number of tests.  They also double-checked that the groups of dogs were matched on physiological variables; here the only difference was that dogs in Group C (APDT trainers) had higher levels of salivary cortisol at the start of the study, potentially indicating that they were more stressed before the study began.

Some of the results showed differences in training style. The dogs spent more time sitting, interacted less with the environment, and the trainers issued more commands, for Groups A (e-collar) and B compared to Group C (APDT rewards-based). Lip licking associated with food was higher in Group C than for Groups A and B (this makes me wonder if fewer treats were delivered to Group B although this is not reported on).

The results also showed some welfare concerns. The dogs in Group A (e-collar) were more tense, yawned more (a sign of stress) and spent less time interacting with the environment than the dogs in Group C (APDT rewards-based). For dogs in Group A, the number of yelps and other vocalizations increased with higher levels of shock. 

At three months after the training, dogs in Group A had higher salivary cortisol levels than dogs in Groups B and C when they arrived at the training centre, which may suggest the anticipation of e-collar use. Most owners from all groups were satisfied with the results of the training. 

The report says “the study did find behavioural evidence that use of e-collars negatively impacted on the welfare of some dogs during training even when training was conducted by professional trainers using relatively benign training programmes advised by e-collar advocates.” (p4) They also found that the e-collar was not more effective than rewards-based training for recall and chasing, even though this is the scenario that e-collar advocates particularly recommend it for.

Unfortunately we can’t say that no dogs were harmed during the course of this research, as the findings are clearly that e-collars can have negative welfare consequences. However the research was conducted following ethical guidelines, dogs were monitored carefully, and for ethical reasons intentional misuse of the e-collar was not studied. While the owners who used e-collars did not follow manufacturer’s guidelines, it is worth noting that the three dog trainers who took part in pilot work on sheep chasing did not follow the guidelines either. 

Previous studies have also found welfare issues with the use of e-collars (e.g. Schilder and van der Borg 2004; Schalke et al 2007; Herron et al 2009). A large survey of 3,897 dog owners in the UK (Blackwell et al 2012) found that 3.3% reported using an e-collar in training. Amongst the owners of dogs who had had recall and chasing problems, those who had used e-collars reported significantly less success than those who had used rewards-based methods. 

The first Defra study found wide variability in how e-collars were used, and showed that owners either did not read or did not follow the advice given in the manuals. There were significant negative welfare findings in some dogs trained using the e-collar. The second study, designed to use the e-collars by trained professionals, according to industry standards, and for only a short period of time, also found a negative effect on animal welfare.  

In addition, excellent results were achieved by using reward-based training, which shows the e-collar is unnecessary. Of course, the many people who have already trained a strong recall using positive reinforcement will not be surprised by this. However, it will surprise some shock collar advocates, and they should be encouraged and supported to learn modern dog training techniques.

These studies will increase the pressure on governments to ban the use of e-collars, particularly in the UK where taxpayers funded this research. Since dog training is an unlicensed profession, owners should check the credentials of dog trainers carefully, especially since trainers who use shock collars may not make this clear on their website. In the UK, the APDT is against aversive methods, and around the world (including the USA) the Pet Professional Guild is committed to force-free training. Check out my article on how to choose a dog trainer.

If you enjoyed this post, you will also like positive reinforcement is more effective than electronic collars (an update on this research) and a scientific review that calls for shock collars to be banned in Europe and outlines the reasons why.

What do you think about these results? Do you think shock collars should have warning labels? Or do you think they should be banned?

Blackwell, E. J., Bolster, C., Richards, G., Loftus, B. A., & Casey, R. A. (2012). The use of electronic collars for training domestic dogs: estimated prevalence, reasons and risk factors for use, and owner perceived success as compared to other training methods. BMC Veterinary Research, 8, 1-11.
Defra AW1402 (2013) Studies to assess the effect of pet training aids, specifically remote static pulse systems, on the welfare of domestic dogs. University of Lincoln / University of Bristol / Food and Environment Research Agency.  Final report prepared by Prof. Jonathan Cooper, Dr. Hannah Wright, Prof. Daniel Mills (University of Lincoln); Dr. Rachel Casey, Dr. Emily Blackwell (University of Bristol); Katja van Driel (Food and Environment Research Agency); Dr. Jeff Lines (Silsoe Livestock System).
Defra AW1402a (2013) Studies to assess the effect of pet training aids, specifically remote static pulse systems, on the welfare of domestic dogs; field study of dogs in training. Final report prepared by Prof. Jonathan Cooper, Dr. Nina Cracknell, Jessica Hardiman and Prof. Daniel Mills (University of Lincoln).
Herron, M. E., Shofer, F. S., & Reisner, I. R. (2009). Survey of the use and outcome of confrontational and non-confrontational training methods in client-owned dogs showing undesired behaviors. Applied Animal Behaviour Science, 117(1-2), 47-54.
Schalke, E., Stichnoth, J., Ott, S., & Jones-Baade, R. (2007). Clinical signs caused by the use of electric training collars on dogs in everyday life situations. Applied Animal Behaviour Science, 105(4), 369-380.
Schilder, M. B., & van der Borg, J. A. (2004). Training dogs with help of the shock collar: short and long term behavioural effects. Applied Animal Behaviour Science, 85(3-4), 319-334.
Photo: Ksenia Raykova (

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