Hi there! Thanks for getting in touch! Sounds like you’ve got quite a situation on your hands.
It’s hard to diagnose from afar, but from the few clues you’ve given me, I could hypothesise that this dog’s behaviour comes from the three following problems – this is how I would address them.
1 – A lack of socialisation
Perhaps your friends have started the socialisation process but haven’t gone far enough. Socialisation doesn’t just happen at puppyhood; it can and should continue throughout a dog’s life. Explain to your friends that the more they go to new places, the more they meet new people, and the more they confront their dog to new situations, the more their dog will be prepared for anything. A dog that stays home and sees the same people all the time tends to become nervous in new situations very easily – and this could lead to aggressivity.
2 – A lack of confidence
Nervousness and anxiety often comes from a lack of confidence. To build up a dog’s confidence, the best thing to do is to work on training. Ask your friends how many commands their dog knows. As a Border Collie, this dog should be constantly mentally challenged. By teaching their dog commands or tricks, they are not only taking care of his mental health, but also strengthening their dog-owner bond – both of which help to build a dog’s confidence. It goes without saying that the training should be based on positive reinforcement methods.
3 – Some sort of anxiety that may be rooted in a traumatic past experience
You mention that one of your friends “doesn’t understand the concept of positive reinforcement”. If this owner has ever used punishment or force while trying to handle or communicate with the dog, it could be that this traumatised the dog (Border Collies are particularly sensitive, too). If the dog has built up a sensitivity to people, you’re going to have to work on de-sensitising him. Tell your friends to go see a behaviourist or professional trainer for this, as they’ll need someone experienced who can see first-hand how the dog behaves.
Hope this helps. Best of luck!
Justine Seraphin, BSc (Hons) Animal Behaviour and Welfare