Aggression is defined as a threat, challenge or attack that is directed towards one or more individuals. Signs of aggression may be visual (changes in body posture, piloerection – hair raises up) and auditory (growling, barking) and may involve the use of teeth and occasionally claws.
All behaviour is dependent on the influences of inheritance, learning and the environment. Aggression may be normal or abnormal depending on the context. It is important for dog owners to be aware that aggression can be caused by underlying fear and anxiety.
Several forms of aggression have been recognised in dogs including:
- Territorial aggression – the dog protects the property by barking, growling, snarling, biting
- Predatory aggression – the dog silently stalks small animals, birds. It may also stalk infants and drooling is a common sign
- Fear aggression – the dog may bark, growl, snarl while backing up in a response to people, or other animals. The dog shows fearful body posture, with its tail and ears down. The dog may bite from behind and run away. It looks for escape routes when cornered
- Pain aggression – usually in response to being manipulated or an aversive event
- Sibling rivalry aggression – dogs living in the same household may not get along
- Sexually-related aggression – usually occurs between intact male dogs
The assertions that specific breeds of dog (and all individuals within those breeds) will be aggressive are unsubstantiated by scientific studies. RSPCA Australia considers that any dog of any size, breed or mixture of breeds may be dangerous and thus dogs should not be declared dangerous on the basis of breed.
How can aggression be treated?
Aggression can be successfully treated and managed. To do this however, it is critical to diagnose the type of aggression and its ‘triggers’ – the stimuli that provoke the aggressive behaviour. We highly recommend that you consult your veterinarian who can help you or can refer you to a veterinary behavioural specialist for assessment and treatment.
Treatment for aggression often involves behavioural modification techniques. These techniques use positive reinforcement as the basis – reward ‘good’ behaviour and avoid reinforcing ‘unwanted’ behaviour. Treatment for aggression generally does not involve the owner ‘punishing’, using aversion therapy or being aggressive towards the dog as this is likely to make the dog’s aggressive behaviour worse.
For example, a fearful dog being walked on leash may become anxious upon seeing an unfamiliar dog at a distance, and react by becoming more aggressive as it approaches. The fact that the dog is constrained to a leash may increase its stress levels, as the dog perceives its escape options to be limited. If the owner chooses to scold or punish the dog at this stage, it could cause the dog to associate unfamiliar people or dogs with both punishment and fear, thereby reinforcing the anxiety-related aggression and making it worse.