There are many types of aggression in dogs and in order to be able to deal with the behavioral issue you need to identify the cause of the aggression.
For example there are three main categories that the displays of agression can be classed into:
Fig is a rescue dog that was a stray, he is also a cross breed of more than one type of terrier. The hunting instinct in him is very strong and it has been quite a challenge to get this undesirable behavior under control. Our dog training manual has been invaluable in helping us to resolve this issue (once we identified where the behavior was coming from) and I will talk about it further in future posts.