Dogs can show aggression by biting or stealing food. An aggressive dog often needs more exercise, socialization, or may suffer from health issues.
Trauma, poor breeding, and lack of socialization are the fundamental causes of aggressive behavior.
Training can modify that behavior by desensitizing the dog to stimuli that make them fearful, angry and out of control.
Watch for aggressive puppy warning signs including snarling, growling, mounting, snapping, nipping, lip curling, lunging, dominance, challenging stance, dead-eye stare, aggressive barking, possessiveness, and of course, biting.
Never excuse or ignore the behavior of an aggressive puppy. Without help, there is little doubt an aggressive puppy will become a dangerous dog.