1.Caused by drugs- Medication can bring about changes in a dog’s perception and this in turn may cause the aggressive behavior.

2.Encephalopathic- a medical condition in the dog’s brain like epilepsy is the cause of the aggression.

3.fear-induced- A situation that places the dog in a position that makes him think that he is fighting for his life.

4.Food guarding- The dog has an impression that people are going to take his food instead of giving him some.

5.Wrong and improper socialization- Dogs that have been isolated as puppies may show aggressive behavior in situations that they are not familiar with.