Hi Kebars - thanks for the reply.

We are going to sort out the garden this week in terms of fencing - it was pretty secure, but he managed to force his head through a couple of tiny holes that we hadn't noticed and then pushed through with sheer brute strength rather than dig - we are getting six foot panels so it should cure that problem.

I suspect that the other dog he can here is a bitch on heat and that he is trying to get through to her - from what I've read, even though he has been neutered, it can take a while for this instinct to dampen down.

I understand what you are saying about the cat, but that's the thing, he's not obsessed with her - he doesn't stare at her, and if they are both in the garden and she doesn't leg it, he'll have a quick sniff and that will be it. When he tries to eat her food, he never does it while she is eating. The attack seemed to be provoked by the sound of her coming in through the cat-flap. We've started to do a bit of training to stop him reacting to the sound of the cat-flap, so maybe that will help.

I'll see what the behviourist says next week - I really hope we don't have to take him back