I wonder if anyone can help me. We have a lovely 7 year old Portuguese Water Dog who has always had the most tolerant and laid back temperament. However, over the last year he has got increasingly bulshy and has started to show aggression to other dogs and now to people. We have just returned from holiday leaving Kev with some friends he has known and stayed with many, many times and sadly they told us that he bit a young girl quite badly and drew blood. Luckily the girl is ok and she and her parents have dogs and are very understanding. But, we are very concerned and puzzled and really dont quite know what to do next. He has also started showing signs of aggression to the vet and she now insists on muzzling him. Does anyone have any words of wisdom as to what might make a normally laid back chap turn aggressive? I feel quite sick at the thought that I can no longer trust him and am desperately worried about him.