From the very first moments of its popularity, more and more persons have argued upon the negative psychological effects that this anti-bark collar can have on a dog that is punished for doing something natural to them and that, even more confusing, is meant to protect their owners.
It was scientifically proven that, even though there is no physical harm, this puzzling state in which the dogs find themselves for unexplainable reasons can lead to stress, anxiety and even aggression. Just like the invisible fences – another extremely controversial product – citronella collars are used with the purpose of stopping dogs from doing what they are best at: exploring certain areas and barking (even though for reasons known only by them) in order to protect/alarm/caution their owners.
This way, by being punished through the annoying sound and smell of the spray, the dogs can develop a certain inhibition and fear of barking in general. And I think that everyone agrees that this is not a state that you would like to put your best friend in.