I have 3 dogs - Choc Lab, Collie and a Rottador (Lab/Rott Cross). The Choc and Collie I have had from pups, from the Rottador was a rescue when we got him at 8 months old. He had bought originally by drug addicts who had abused him.

At the start was the Collie (who is now 3) and then we got the Rott as a rescue (Who is now 3). Similar ages, at first they got on together ok, but the Rott has always had an 'attitude problem' shall we say, alarm barking, aggression over toys. This would come to ahead that when we took them out and let them off the lead, he would jealously try and fend my collie off from playing with other dogs by chasing him and biting into his side or aggressively barking into his ear. This creates worried looks when people see the 2 dogs hurtling towards their dogs, one wants to play the other wants to stop one from playing.

On 2 occasions, the rott has bitten the collie, this has required an operation and stitches both times in these pursuits.

Since we got the choc lab as a pup, he has not bothered with it and even plays with it happily. I suspect since the choc lab is 10kg heavier than him he is a bit more wary.

The aggression still persists, such as grumbling when getting off of furniture or sneaking onto the bed when he clearly knows that it outside his boundaries. If he 'steals' anything he hides under the bed and bears teeth, growls if you try and retrieve it.

I have most things, not hitting him, showing affection, asking him nicely but this turn of aggression still exists. What is more worrying is my wife is almost 30 weeks pregnant, and as much as an animal lover that she is, she is getting extremely worried that 1 second alone with the baby he might attack it.

At the moment he is on the lead and I don't trust him off it. I have phoned the dog rescue we got him from (no answer - Sunday) and have set him strict boundaries, he is actually a very loving dog in the house, affectionate, and at times quiet, but it is so Jekyll and Hyde turn of mood that is worrying us the most.

Is this something that we can ever train out? or should after 2 years of having him return him to the trust (which would break both mine and my wifes heart to do). I already understand that we can't risk the baby at all.

Advice appreciated.

Michael