Does your dog bark at people or dogs from inside your house? If so, you need to be aware what your dog is learning.
I'm cheating a bit as this dog is a colleague's dog and has been taught to do this!
If dogs bark at something passing their territory, this is usually doggy speak for “Go away scary thing, don’t come near my home.” This behaviour is usually quickly rewarded by the disappearance of the aforementioned scary thing! A good example of this is the postman. We might not realise it, but this behaviour is aggressive. Perhaps “Go away scary thing” is not the best way to phrase what the dog is saying; it’s actually something far less polite!!!
Barking aggressively at these things gets rewarded as it works because the scary thing disappears (he wasn’t to know it would disappear anyway), so the dog becomes more confident in using this behaviour to keep himself safe. Be aware that practice makes perfect!
The more the dog practices this behaviour, the more sure he is that he can deal with the perceived threat. It’s only a matter of time before he will manage to get out of the door whilst the scary thing is passing, and BOOM! He has now delivered a nasty bite! The owner is surprised as the dog has not been considered aggressive before. The window was preventing him from getting out all this time, but as soon as he got the first chance to deal with the threat, he dealt with it in the way dogs do – by biting. Some may be surprised that a fearful dog would run up to a scary person. However, the dog has been learning that barking aggressively makes the scary things go away for a while so gains confidence in his methods of driving the threat away. With built up frustration and practice, it really is only a matter of time before the dog gets out and bites someone. Sadly, the owners are horrified it happened, never realising what this behaviour was. Nobody wants to believe their dog could bite. But if your dog is barking at passers-by, the writing is already on the wall.
So, if you have a dog that barks aggressively out of your home window/porch/conservatory/gate at passers-by, what should you do about it? Does this mean the dog will be aggressive when not on his property?
It’s only territorial aggression if the aggressive behaviour is only shown to people/dogs when the dog is on or near his own property. If he is friendly at all other times, this would class as territorial aggression. However, if the dog is not friendly with strangers and dogs at other times, it’s not territorial; it’s fear of people/dogs wherever they are. The dog may feel safer and more supported in his home territory hence expressing his opinion, whereas he may be more closed down away from his safe place and not show aggression… yet. Maturity can change things and as dogs mature they can develop adult dog skills, like biting. When younger, fearful dogs avoid trouble if they can, but then start to defend themselves if necessary when adult, or if avoidance doesn't work.
So, if you have a dog that barks aggressively at people/dogs when they pass or approach his house, the easiest thing to do is to remove his access, as soon as possible, to the ongoing sight of people/dogs passing his home so that he cannot keep practising this behaviour and perfect his technique. This should prevent the need to defend his territory and stop the behaviour from becoming more problematic.
If you do not want your dog to bite it is best to keep your dog in another space away from the front door when you have visitors arriving until you are sure he will not defend his space. If you are not sure, then make sure the dog is kept away from visitors to ensure their safety. It is a criminal offence for your dog to show aggression to anyone in your home or garden in England.
It is always best to seek the guidance of a properly qualified dog behaviourist. So, find a behaviourist that is a member of an organisation that has assessed them as competent, not someone who just pronounces they are qualified without a qualified opinion. Be aware that a dog trainer is NOT a behaviourist, these are different skills and require a different level of education. The industry is not yet regulated so it can be difficult to know who to trust. If in doubt, ask your vet for a referral to a qualified behaviourist.