1 Increased Fear And Anxiety
: Especially if punishment is inconsistent or harsh , your dog will become anxious or fearful because it doesnt actually know why it was punished . After all, from your dog's perspective the behaviour was natural and appropriate and gets it something it wants - eg bark at a passerby whom is percieved as a threat, passersby leaves . Punishment will make your dog fearful of you or some item or context it associates with the consequence . Eg if I tipped a bucket of spiders over your head, you may become fearful of buckets as well as me. If your dog is punished for barking at the passerby, it will become more fearful and reactive of passersby. It will cease to try new behaviours for fear of getting it wrong and being punished .
2 Aggression And Defensive Behaviour
: Your dog will react to what it percieves as a personal threat by defending itself . It will start to get in first and bite BEFORE it can be hurt . This is then labelled an " unprovoked bite ".
3 Breakdown Of Relationship.
:Punishment willl erode trust and cause your dog to be wary of interaction with you.Cooperation will be decreased . Your dog will become difficult to train because your bond has been damaged .
4 Behaviour Suppression.
:Punishment will shut down behaviour and may seem to improve compliance in the short term -but is ineffective for long term behavioir change . Your dog will not learn an alternative acceptable behaviour from being punished . At best it will learn not to do the behaviour in front of you .