Has this ever happened to you? A friend comes over to visit and, the next thing you know, your dog is jumping up on him to say hello. While it's embarrassing for you, it is annoying and sometimes frightening to your guest. Teaching your pooch to keep all four paws on the floor is part of being a responsible dog owner. It's also relatively easy to do. This is a good thing, because while some dogs are simply jumping up in excitement -- others are using it as a way to show you who's the boss. Here's what I mean...

If you have a dog that growls or acts aggressively towards strangers, it's not too late to do something about it. But first, you should understand why your dog's acting this way. Your dog's ancestors were aggressive by nature. Living in the wild meant having to hunt for food, and defend themselves from other animals. It was instinct to protect their resources like food, mate and territory.

Fortunately, selective breeding over the centuries has minimized and refined this trait significantly. Even so, it's important to understand that by nature, all dogs are physically capable of inflicting serious harm. One look at those teeth and you know this is true! While aggression is part instinctive, there is much you can do to prevent it from becoming a problem in your dog. If (for some reason) this aggression does surface, there are definite things you can do to deal with the problem.