I think most of this could be their difference in ages. I have a 2 year old and a 7 month old. The older dog doesn't want to play anything like as much as the younger pup. So I have complete 'no go' areas where Tatze (older dog) is allowed and Twiglet isn't. Twiglet is not allowed near Tatze when she's in her crate, on her chair or on my sofa. That way the older dog knows she can have some peace whenever she needs it. Tatze launches on to her chair when she's had enough and Twiglet is learning to amuse herself. When our first pup arrived Tatze was only 15 months old - but, even then, the difference in playfulness was noticeable. By the time Gypsy was 10 months Tatze definitely needed her own space. If I were you I would take charge of the space so that your younger dog knows YOU decide who goes where and your older dog knows that she will never have to interact with him if she chooses not to. Use treats to train this. I have an 'enough' command which I taught with very yummy treats (tripe sticks) - it works but takes a long time (6 weeks or more) to teach. It's worth it!
Hi there, and welcome to the forum. This is clearly really upsetting for you. I am no expert, but it sounds like a separation anxiety. How is he if you walk him on his own? What kind of "brain training" have you tried with him, and what did he do? I'm not sure really any of us will be able to help greatly other than advise you to contact a local behaviourist who will be able to see him in the flesh, how he reacts, and hopefully give some more practical advice. jac
PaigeEmily I have to apologise, but there was a duplicate post here that I tried to merge, and somehow it has wiped your original. I am so sorry, but am trying to get help to fix it. No idea how it happened. Hope I can sort it. jacqui