My friend’s father told me he thinks his Yorkshire terrier is racist because whenever they encounter a person possessing dark skin the dog behaves aggressively. So I asked my friend’s father. “How many people of dark skin do you and your dog encounter on a daily basis?” He replied “none. Only occasionally do we encounter someone with dark skin.” Therein lays the answer. Dogs are often afraid of types of people to which they are not accustomed.
Another false assumption people will make is that their rescue dog was abused by a man, a child, a woman, a person of certain stature, a person of certain skin color, a person in uniform etc, etc, if their rescue dog behaves aggressively in front of said person when most likely the dog just finds a particular trait unusual, therefore scary. For example, it is not uncommon for dogs to behave aggressively in the presence of children because their stature and their mannerisms are so different from that of adults.
I always encourage my clients to let go of any preconceived notions they might have that their dog is racist or has been abused by a certain type of person in an effort to stop excusing the unwanted behavior and begin to learn a proper way to deal with the issue when it arises. Speculating about racism, a trait of which a dog is not capable or speculating about past abusers will never aid in the rehabilitation and growth of a dog behaving aggressively toward certain types of people. Exposure with positive association or experience, training and proper management are the tools needed to tackle this common issue.