Hi. I am in desperate need of some advice. I have got an 18 month cocker spaniel. I have had her since she was a puppy and took her to dog training classes for a few months. Walking her was a pleasure. She was sociable with children,adults and other dogs. About 2/3 months ago we started to notice a change in her behaviour. Whilst out on a walk she was off of the lead and a dog came up and growled at her and she pinned it to the floor. I was so shocked as I had never seen this before and it was conpletely out of character. Since then she has started barking at children, been aggressive towards others dogs and does not stop barking(quite aggresively)at visitors who come into the house. There is a dog next door and if she knows he is out in the garden she will bark quite aggresively at the dog but her tail will still be wagging. If I go to stop her whilst she is doing this then she will go for me or my partner. Because of this, over the last few months we have been very aware of making sure that she knows who is boss due the "pack" mentality. She is also very good with commands so its not that she is not obidient. It is just so hard because 2 months ago she was the perfect dog whereas now I am starting to resent her. i cant think of anything we have done to make her the way she is. I have grown up with dogs and I know that they can be hard work at times but I am starting to question whetehr she will change? She has never bitten anybody but I wonder is that coming next. I really want to get things back to how they were and enjoy her rather than worrying what she's going to do next. Whats hard to understand is that with me and my family she is such a loving gentle dog and then out of nowhere she changes and thats what makes me nervous around her because she is unpredictable........please help.