Thanks for the advice! Digby seems to be the dominant dog but is also less secure (if off lead around other dogs, he will keep on checking on us where Romulus is more independant). This morning I tried a bit of heelwork on our walk and Digby will pull on the leash and break the heel command. As soon as you do an about turn or make him sit, the distance between him and Romulus increases and Digby starts breaking the sit command and pulling to get to his brother. I don't know what the previous owners did to them but I kept Digby in heel after we got inside our property and he suddenly put his head down, sat down and wouldn't move. I'm glad to say that I ignored him, kept the leash tight and continued telling him to heel. Eventually he moved forward and looked at me and I then praised him. I then made him sit and lie down with strong verbal praise and he seemed to be a bit happier. Oh well, we have a long road ahead of us to get them to trust us but it is early days!