24 June 2023

Woof woof ... who goes there?

Back in 2011, I wrote an a general article about barking that covered aspects such as why dogs bark, different types of bark and what they mean, and some guidance to help reduce or resolve problematic barking. Having joined various Romanian rescue dog chat groups and forums following our own recent Romanian rescue dog additions, I have been getting to know the problems and struggles experienced by other Romanian rescue dog owners  one of which is habitual barking and/or threatening behaviour towards strangers and familiar visitors to the home that is either slow to respond to training, or doesn't respond at all. When I was still working as a dog behaviour psychologist, this was one of the most problematic behaviours I encountered with client dogs. It is called 'extra-familial aggression'. If misunderstood or mismanaged, extra-familial aggression has the full potential to land owners in serious trouble if their dog bites a visitor to the home. 

As with other specific (as opposed to general) behaviours, I produced my own handout for clients so that they could understand the psychology behind the behaviour. Fast forward to 2023, and what I find concerning is that extra-familial aggression and its (often) precursor 'watchdog behaviour' don't appear to be part of today's dog behaviourists' vocabularies. Certainly I have yet to see another dog behaviourist use these terms when commenting on 'barking/lunging at visitors to the home when they get up to move/leave' type posts. I have also heard the behaviour in one dog that had stacked up a four-bite history – two of which landed the owner's (different) guests in hospital  being incorrectly identified by an (otherwise) experienced dog behaviourist as separation-related. Maybe extra-familial aggression isn't covered in today's canine psychology courses. Maybe it's because the term 'reactivity' has become the preferred buzzword for pretty much anything shouty and threatening, including aggression. I'm only guessing. But in any case, I hope that this article might help to address the apparent gap in understanding. The following is adapted from my 2010 'Watchdog and Extra-Familial Aggression' handout:


Alarm barking and threat barking are normal and useful when expressed appropriately. Indeed, most dog owners welcome some alarm barking and household protection as an added benefit of dog ownership. However, ‘watchdog behaviour’ more often than not has very little to do with protecting or defending a dog's territory or people, rather it is ‘auto-protective’ in nature and can be likened to a ‘who goes there – friend or foe’ reaction.

Normally, social novelty such as strangers and familiar visitors evokes excitement and ‘approach-avoidance conflict’ in dogs causing them to bark, followed by friendly resolution and approach, social investigation, and the initiation of reward-seeking behaviour. It is highly unlikely that watchdog behaviour in a well-socialised, well-trained dog will generate a further shift in auto-protective arousal that sets off reactive, impulsive and difficult to control alarm and threat behaviours if understood and handled appropriately, e.g. not punishing the dog for barking but instead using distraction in conjunction with teaching the dog ‘quiet’ for barking in the garden, working on a highly rewarding recall to use when the dog is taken by surprise by a stranger when out walking, or in the case of watchdog barking when visitors come to the house, using barriers such as pens and stairgates to initially keep dogs and visitors apart, giving the dog time and space to adjust to the change in social dynamic and become less aroused, and owners the opportunity to use positive association training such as ‘Look At That’ (LAT) so that visitors and guests are viewed as a good thing.


Watchdog behaviour becomes a problem when the normal, familiar pattern of friendly proactive and pro-social behaviour is disrupted, causing auto-protective arousal to escalate into earnest aggression. When watchdog behaviour shifts in this way, it is known as ‘extra-familial aggression'. Instead of merely hesitating and barking (ritualising) before approaching and initiating pro-social introductory and exploratory behaviour, the extra-familial aggressor shifts instantly from alarm-arousal evoked by the sudden presence of a stranger or familiar visitor, to a confrontational orientation, transforming that person into an object for the discharge of aggressive tensions and threats.

These reactive, extra-familial aggressors fall into two camps – those with a ‘flexible (habituating) watchdog script’ and those with a ‘rigid (non-habituating) watchdog script’:

FLEXIBLE WATCHDOG SCRIPT  Most extra-familial aggressors fall into the ‘flexible watchdog script’ camp, warming up slowly to strangers and familiar visitors, accepting their approach and contact with tolerance, and finally initiating and maintaining friendly behaviour for the entire duration of that interaction.

RIGID WATCHDOG SCRIPT  Extra-familial aggressors with a ‘rigid watchdog script’ may resist a stranger’s or visitor’s approach and remain persistently on guard, even after repeated uneventful meetings or visits. Those with rigid watchdog scripts present a serious problem. These dogs clearly recognise and distinguish ‘insiders’ and ‘outsiders’, and whilst they may appear to warm up to visitors and even accept food and other rewards representing friendly intent, they will suddenly become aggressively aroused and threaten to bite the person as they get up, move towards the owner, or attack them from behind when they walk away or leave the house. It is essential to understand that such aggressive behaviour in response to an upturn of activity and sudden change appear to implicate a sympathovagal mechanism and may be related to rapid shifts in autonomic arousal, meaning that the behaviour is involuntary and not under the dog’s conscious control. It cannot be resolved with training. Some rigid watchdog script extra-familial aggressors may display few (if any) obvious threats and attack silently.

Normal watchdog behaviour may escalate into extra-familial aggression in the presence of ongoing events and noise that provoke excessive alarm and threat barking, particularly those that the dog can’t make a visual connection to, for example, building noise and associated comings and goings from a neighbouring property. The effect of stress on the body is cumulative. Socially dense situations, under-stimulation, over-stimulation, confusing or conflicting communication and lack of quality rest and sleep as well as repeated watchdog barking behaviour causes stress hormone levels to rise and remain high, which has the effect over time of lowering emotional tolerance and impulse thresholds. Before long, a shift in behaviour occurs, with what used to be alarm barking or silent tolerance towards visitors giving way to extra-familial aggression.

Watchdogs who bark and threaten will usually follow a flexible watchdog script. Occasionally a dog is unbalanced sufficiently for a rigid watchdog script to occur, which is usually the point at which an owner will label the dog’s behaviour as being ‘out of character’.

Extra-familial aggressors that fall into the rigid watchdog script camp require life-long supervision, control and appropriate restraint to avoid future attacks when exposed to unfamiliar visitors and familiar outsiders. If an extra-familial aggressor has in the past truly followed a flexible watchdog script, re-habituation may be possible with an intensive, reward-based behaviour modification programme involving impulse control training combined with efforts to reduce the dog’s daily stress, moderate daily exercise, daily play, posture facilitated relaxation training and if appropriate, dietary change or supplementation.

Any dog of any breed can show normal watchdog behaviour. Equally, there are many, many individual dogs that don’t display watchdog behaviour at all. However, I have found that the incidence of extra-familial aggression with a rigid watchdog script is higher in high-energy, high-drive working breeds such as livestock guardians, collies and terriers. If I have described your dog here  if you believe that it fits the description of 'extra-familial aggressor with a rigid-watchdog script'  please keep it safety away from ALL visitors to the home.