Spotting Aggression in Dogs.

Sometimes dog behavior might be hard to interpret.  The dog is wagging his tail, is he happy or nervous?  Aggressive or passive?  Here are some tips on spotting aggression in a dog:

• The dog's tail is wagging slowly and is straight up in the air.  The dog may also appear stiff when moving.  This can be a sign of a very territorial dog.  It is important not to run, in fact stay as still as possible.  Let the dog walk around you, don't make eye contact sudden moves or noises.  Hopefully he will just move on.  If you find yourself in his space by accident slowly back away until you are in a safe place away from his territory.
• The dog's tail wags between his hindquarters.  He may crouch close to the ground.  This is a sign of a nervous dog.  They can be unpredictable and could react with aggression in response to your actions.  Sudden movements, mostly toward the dog, can cause a anxious dog to react in fear.  It is best to leave this type of dog alone.  Most will avoid you.  
• Lastly, if the dog's tail is stiff, his lips are drawn back,teeth showing and the hair on his back is standing up.......Stop, drop your eyes to the ground, and very, very slowly inch backward until you can get away!

One last piece of information....more people get bit by small dogs than large: just because they're small doesn't mean they won't be aggressive.  :)  Watch your fingers.