Aggression can start at any age in a dog.
You might look at this puppy and think how cute is he, but underneath that puppy eyed exterior lies an aggressive dominant dog. At 10 weeks of age his owners couldn’t believe the aggression he displayed during our lesson. At home he’s been nipping and biting family members. As new dog owners they perceived it to be just puppy biting, so when he nibbled fingers they thought that was ok too. In fact any teeth on skin is a bite. Adults are the worse as they see a nibble as acceptable. I always ask the question “if that was a week old baby would you see it as nibbling or your dog has just bit your baby”, we all know the answer to that.
2 weeks of a dogs life is multiplied by 6 which means they are learning good and bad habits at a fast rate. If we do not start off with the knowledge and understanding of the breed traits and basic structure and boundaries then we will always have a disobedient dominant dog.
Starting early is the key to success, more importantly finding the right trainer to help is paramount.