In some cultures and languages, using "dog" to curse people may be because the image or characteristics of dogs in some aspects are used by people to metaphorically describe negative qualities or behaviors. Here are some possible reasons:

Loyalty and betrayal: Dogs are usually considered loyal animals, but in some cases, people may Will use "dog" to describe betrayal or disloyal behavior.

Inferior and despicable: In some cultures, dogs may be viewed as inferior or despicable animals, so using "dog" as a curse word may imply that the other person has similar qualities.

Wild and uncontrolled: The wild and uncontrolled side of dogs may be used to describe people's misbehavior or lack of self-control.

Negative associations: Certain words or phrases related to dogs, such as "dog shit" and "bastard", may themselves be derogatory and insulting.