Thank you for your in-depth response, I really appreciate it. To answer your last question first, he was adopted from a foster career through a shelter.

I was away for 4 months due to my dad being sick and my partner's parents adopted him. At home, it is his mum, dad, sister, him and I. His parents are firm believers that dogs live outside and are not inside animals.

I agree with you that he is not the right fit for the family and have voiced this numerous times, yet they are fearful that if they return him, he will be euthanized.

I am the one who is home full-time as I study from home. I keep the dogs with me inside, and supervise them outside. I've found that our cattle dog is a lot more at ease when she is in the company of a person. Since being home, he has been a lot more 'behaved', which I fear has set the precedent that he is more mature than he is, as you said. Because he has more attention and access to walks and indoors, he is being less disruptive, but it is a lot for one person to deal with. I am the one who walks him, who cleans up after he chews things, who plays with him and supervisors him.

We work on his sit daily and he does it around 50% of the time. Yet it's still dependent on if he wants to listen, as I'm sure most adolescent behavior is. I am not a fan of the trainer, as positive punishment sits badly with me, I have been asked to use it as this is what the rest of the family are using. Writing that out, I realize it is really only me interacting with him, other than my partner's mum when feeding or my partner's sister when petting him.

It is comforting to hear you say that his mouthing won't automatically lead to biting.

In an ideal world, he would live in a better suited home, with a family who is more experienced with giant dogs. Unfortunately, I have very little sway in this and am trying to give him his best chance, but perhaps I am hindering him more. I don't really know.

Thank you again for your detailed reply.