1. A conditioned fear response from the past. Person reacts with a high level back. Dog reacts with fear to a jogger on a walk. Person gets anxious, embarrassed, stressed. Person makes the situation worse because they're increasing the thinking levels.
2. Person has a lot going on and is overthinking. They both spiral out of control and react to eachother.
3. Life Attraction. The animal's life experience and person's life experience are similar. (Both share feelings of abandonment, etc...similar types are drawn to eachother)