I am sure that most, if not all of us dog loving people, have either had a dog that was aggressive, or experienced aggression from a dog of someone else.
I am writing this post so you can learn, recognize, and prevent aggressive behavior from your own dog, and other dogs you might encounter.
There are also a couple of dog training techniques I would like to share with you.
How to recognize body language, and aggressive dog behavior

• If your dog seems uneasy or skittish, this means your dog is scared and might lead to aggression.
  
• If you dog moves toward another dog slowly and stiffly.
  
• Your dog leans forward toward another dog and makes himself look bigger.
  ex.
  arching his back, widened stance, head, tail, and ears are raised up.
  
• Your dog stares very intensely at another dog.
  
• The most obvious, if your dog growls at another dog, and bears its teeth.
  

How to prevent aggression using socialization (yes, back to the all important socialization)

• Socialization early on is the number one defence in aggressive behavior towards other dogs, and people.
  
• The more dogs he meets in different situations the better
• Do not shelter your puppy from other dogs, this is when he learns proper etiquette to the all important social ranking.
  Which brings me to my next point.
  

Aggression is common when trying to determine social rank.

• When two dogs of the same sex, age, and size try to assume a higher rank, aggression and maybe a little fight might occur.
  
• If this happens stay out of it.
  A noisy fight is a good sign that the dogs have good bite control.
  
• If it is a quiet fight is a bad sign.
  If you experience this again, stay out of it.
  Try t make a loud noise by shouting, or through some water on them to split them up.
  Usually one dog will give up before an all out fight happens.
  
• But again if your dog is properly socialized he should be submissive and will give the dog showing aggression the higher rank without a fight.
  
• Socialize, Socialize, Socialize!

Avoiding aggressive dog behavior * If your dog is confronted by another dog, keep calm.
Your dog will follow your lead.
* When on a leash keep the leash loose.
If your dog feels tension on the leash his natural reaction is to pull away and even increase your dog's feeling of aggression.
* Do not try to comfort your dog by petting him or give him treats.
Your dog will interpret this as a reward for his behavior and it will reinforce it.
* When in a dog park, let your dog socialize properly before you play fetch with him.
If your dog and another dog go for the same toy it might result in aggression.
But if the rank has already been established you should be free to play.