Why is my dog aggressive towards other dogs?

Dog-to-dog aggression is one of the most common behavioural problems that dog handlers have to deal with, but it is often also a natural response to many situations.

However, as a result of our inability to understand, our fear and the frustration that this aggressive behaviour often triggers in us, we tend to denaturalise it and censure it without asking ourselves what is aggression, why does it happen between dogs and what can we do about it?

What is dog aggressiveness?

Aggressiveness is often understood as a warning or attack response to protect resources or ward off danger or threat (1). However, we forget the second part: canine aggression is also an expression of dog language (2).

This makes marking a dog as aggressive or non-aggressive, more complicated than it seems, because we have to read the context well and understand how and why the animal acts this way. In society, an aggressive dog is one that bites or fights; however, warning signs that precede aggression would also fall under the definition of aggressive behaviour. So, is a dog that shows its teeth or growls to avoid a fight, aggressive? Yes, and that's fine, because aggression is not bad in itself or in all its forms.

Therefore, trained professional or ethologist will assess:

•    Therefore, a trained professional or ethologist will assess: Does it use aggression as its main resource? How fast? What is the function?

•    How much have you reinforced that behaviour as a strategy to protect or gain a resource or to ward off or reduce a threat (another dog)?

Your dog is aggressive towards other dogs because...

An aggressive dog is born and made: This should be clear to you. On the one hand, there is a genetic predisposition towards aggressive behaviour for different reasons, but they fall under the two I have already mentioned:

•    Offensive motivation: your dog wants to protect a territory or a toy and uses aggression to compete or win that resource.

•    Defensive motivation: e.g. fear or insecurity leads the dog to try to move away from the stimulus (another dog, in this case).  

Once we know the motivation, we have to start working along two main lines:

•    On the one hand, we must prevent it from happening again and break the habit as soon as possible. As I am sure you know, a behaviour that is reinforced and works becomes instrumental and encourages further behaviour: To do this, we have to manage the dog's environment and to provide it with behavioural tools that allow us to manage it while we change the aggressive behaviour.

•    on the other hand, We shall change the behaviour, i.e. we shall teach the dog different behavioural alternatives (other behaviours) that achieve the same or better results than what it intends to achieve by being aggressive

Traditionally, however, the aggressive dog has been inhibited (punished), which does not usually work well in intraspecific (dog-dog) aggression because it affects the bond with the handler and does not offer functional (or respectful) alternatives for the dog.  

Modern dog training does not work that way, in fact shows the aggressive dog alternatives for managing the fearful situation while gradually empowering it (the dog in fear) or provides it with more functional options, depriving it of other resources, such as biting (if there is offensive motivation).

Better understanding canine aggression...

In any case, both intraspecific (between dogs) and interspecific canine aggression is In any case, both intraspecific (between dogs) and interspecific canine aggression is one of the most complex behavioural problems to deal with, as a reactive or aggressive dog will always keep the habit and, as handlers, we must carry out a 'lifelong' accompanying work.

For a better understanding, I end this article with an excerpt from the A Treaty on dog aggression by behaviourologist James O’Heare:
« There is no cure for aggressiveness. […] aggressive responses are habit-forming. »

However, we can give the dog tools, eliminate conflict situations and reduce the number of opportunities for these behaviours to occur. By doing all of the above, we will be reducing the possibility that the dog continues resorting to this resource.