Some dog trainers and owners swear by electronic “shock” collars to bring bad habits to heel, despite the devices being banned in some countries. But are they really bad for your pooch? A new study says yes.

The study by researchers at the University of Lincoln in Britain, published in PLOS ONE, suggests that electronic collars, or e-collars, caused the dogs to get stressed.  They found dogs that were trained with e-collars spent significantly more time tense, yawned more often and engaged in less “environmental interaction” compared with other dogs.

“It seems that the routine use of e-collars even in accordance with best practice, as suggested by collar manufacturers, presents a risk to the well-being of pet dogs,”  lead author Jonathan Cooper said in a press release summarizing the study. 

Your local Wal-mart sells an array of “dog shock collars” from the “High Tech Pet Bark Terminator” to the “Electric Fence Collar” and remote training e-collars you can operate from afar with the press of a button.

The collars have a device that delivers short electric shocks to the neck of a dog. The device has different settings that manage the intensity and duration of these shocks.

One brave human on YouTube even demonstrated the full range of shock collar intensity levels, imitating the bark of a dog to see if he could endure the “electric stimuli” used to train our furry companions.

Most devices these days also have “pre-warning” cues such as auditory or vibration signals that come before the electric shock. Used with verbal commands, this trains dogs to avoid the shocks — and the undesirable behavior.

The study found that in some instances trainers often did not use the e-collars according to the manufacturer’s instructions — without pre-warning cues and at high intensity. Where qualified trainers used the e-collar at low settings and with pre-warning clues, the dogs trained using the e-collar still showed some signs of distress compared with dogs trained through other methods.

The 63 pet dogs that participated in the study were split into three groups. One group was trained by industry-approved trainers using e-collars, another trained by the same trainers without e-collars and a third trained by members of the United Kingdom’s Association of Pet Dog Trainers, again without the use of an e-collar.

The dogs were trained for 15 minutes twice a day for 4-5 days. The sessions were recorded on video so researchers could later analyze behavior. Samples of saliva and urine were also collected to measure cortisol — a hormone related to stress – during the training period.

Though the collars are efficient, the study concluded there was no consistent benefit to using electronic shock collars that would outweigh the negative effect on the welfare of any misbehaving mutt.

The authors are Jonathan J. Cooper, Nina Cracknell, Jessica Hardiman, Hannah Wright and Daniel Mills of the School of Life Sciences at the University of Lincoln.