Since Affenpinschers are classed as toy dogs, you might be wondering how these tiny bundles of fur can be thought of as aggressive. Like many breeds that are small in size, Affenpinschers think they are bigger than they are and are fearless. They won't think twice about launching themselves at anything they perceive to be a threat, whether it's a stranger in the home or a Great Dane.
Affenpinschers are very intelligent dogs and may try to manipulate their handlers into getting their way. This could include behavior like keeping just out of arm's reach, struggling during grooming, refusing to let go of objects, running away when he's caught doing something he knows he shouldn't be doing, or even getting his revenge by tearing up papers left out or relieving himself on your bed or your sofa. Leaving these behaviors unchecked could lead to a dog with an aggressive attitude.
Dogs are naturally pack animals, and whether you were aware before or not, bringing an Affenpinscher into your family has just created a new pack! If an Affenpinscher is allowed to get away with destructive or antisocial behavior, he may come to believe that he is the leader of the pack, with the capability of bossing around everyone he comes in contact with, whether it's someone in the family or guests or other pets. Establishing yourself as the leader by rewarding good behavior and discouraging destructive behavior will go a long way in correcting these bad habits and make a happier home for everyone involved.
The best way to avoid this aggressive behavior is to enroll in a "puppy kindergarten" class at the very beginning, or at least find an obedience class you can join with your Affenpinscher. Not only is this a great way to learn the ropes if you haven't owned a dog before, but it's a great way for you to socialize with other dog fanciers, as well as teach your Affenpinscher how to behave around other dogs. These classes will also help you train your dog to respond to basic commands such as sit, stay, down and come.
In between classes, it is best to reward your dog for excellent behavior with positive reinforcement such as treats or toys. Punishment is not recommended as it can lead to the unfortunate "revenge" attitude of your dog. Try to be consistent when giving commands to your dog - they should be the same that you have learned in the obedience class, which will help your Affenpinscher make the link to what he has learned in class.
Finding the right trainer is also going to be integral in your success. Definitely ask friends or colleagues with pets for their advice, ask if you can sit in with a class to see how it is run, and talk to the trainer to find out if he has experience in training toy dogs. Some trainers don't have experience with toy dogs and won't be familiar with alternative methods that may be better suited to them. You don't necessarily have to join the first training class that you find; take your time and find a class that makes you feel comfortable.
Finding the right balance of respect and discipline will make an enormous difference in your relationship with your Affenpinscher. Your dog will be happier when he better understands what is expected of him, and you'll be happier with a well behaved and loving pet.