The answer to which dog breed is the most disloyal really depends on your definition of loyalty. There are many different assessment tools used to measure a dog’s personality or behavior, but to my knowledge, none of these tools measures loyalty. Would you could consider a dog that is aggressive toward strangers to be loyal to you?
By this measure, a dog that is not aggressive to strangers, such as a Golden retriever would be considered disloyal and that’s crazy. Would you consider a dog that displays aggressive behavior towards its owner disloyal? That’s crazy too because some breeds, for example Akitas or Rottweilers, tend to display more dominance, particularly toward less stern owners.