I work in a vet clinic so typically a lot of behaviors I see in my dogs, I ve seen before. This time I can t seem to figure out what they could be fighting over. I have three dogs, two small older male rats terriers and one bigger, younger female pit mix. The boys have been getting into fights lately. One I ve had since he was a puppy and the other we adopted when he was about 7. Both dogs are 9 now and have been living together very well the past 2 years. He would sleep together, play together, its like they were the perfect match. Now lately the adopted boy starts attacking the other completely unprovoked from what I can tell. It happens without any food in the area or previous rough housing or attention to compete over. Sometimes the only thing I can do to stop it is pull him off and he s tried to turn on me when I do. Its like he has a moment were he just loses it and nothing I do or say makes him calm down until I m able to separate them. Im at a loss for what to do. My next step will be to take him to the vet and see if there s anything medically wrong but he hasn t been yet.