| Dogs do not simply "turn". If a normally well-tempered dog of any breed* suddenly becomes aggressive towards its owner (or anyone else) there are only ever one of two explanations:
1) A medical problem. Just as with humans, brain tumours, strokes, and various other health issues can produce personality and behavioural changes. So too can pain.
2) In some extreme circumstances, a dog can become so terrified that it may, out of sheer panic, react aggressively to any approach even by its own owner.
* exceptions being little git breeds like terriers who are frequently 'orrible little objects if they don't want to do something and you make them do it.
More often, when an owner says their dog has "turned" what this really means is that the owner has failed to recognise and deal effectively with a long-running dominance or other issue with the dog. The situation eventually culminates in aggression. Saying that the dog has suddenly "turned" is the owner's way of denying their own responsibility for the dog's behaviour. It makes it all the dog's fault.
Such owners are particularly fond of claiming that the dog inexplicably "turned" when it's attacked someone else.
__________________  Charlie, smiling as usual |