I have recently taken on my mum's dog as her work circumstances changed and she now has to work long hours, leaving the dog on his own for long periods of time for most of the week. We agreed that he would come and live with me as I am home most of the time so have the time to care for him.
He is a labrador x border collie and is 4 and a half years old. He has been with my mum since he was a puppy and has been around my son since he was born and we have never had a problem with him showing aggression towards my son.
He has lived with us for 2 weeks now and has settled in really well, most likely as he already knew us all.
This weekend my partners children came to stay and as soon as he saw them in the house he began to growl and bark at them, his fur became raised and I noticed he was shaking as well.
At first we thought he was nervous as there were new people in his territory and he calmed down with reassurance from us and became able to sit in the same room as the children without growling or barking. But if out of the house for any length of time, he would start the growling and barking upon return again. By the end of the day he had begun to tolerate the children in the room with him but would bark and snap at them at any sudden movement and was not comfortable with them stroking or touching him.
I'm really looking for advice on how to approach and handle this situation. Would it be best to contact a trainer to help us with his behaviour? In the mean time is there anything I can do to encourage positive interaction between them or would it be best to keep them separate? He has never shown behaviour like this towards my son who is 3 but I am now worried about their interactions.
Please no harsh comments as I realise I have been naive not to think of this possibility, I am just looking for advice from others experienced with dogs and their behaviour. Thanks.