I have two wonderful dogs. They get on great, well they did and I wondered if anyone could de-code their behaviour for me? They play fight all the time and its clear that they are playing and both enjoying it. However, for about 3 weeks now things have changed. The only was I can describe it is they are really irritable with each other and sometimes when they play fight for the first time in their lives it turns nasty. Not into a full blown fight but I usually say something and they stop anyway. Can anyone help me to understand what is going on?