[alaskayorkie]

Eddie turned into a toy hoarder when we got Jack, and he would become violent when Jack even looked at "his" toys.

A behaviorist suggested many things, increased exercise first and foremost. But she also suggested leashing him during supervised toy time. When supervised toy time was over, I gathered up all the toys and put them away. Once I took charge, Eddie saw less of a need to be aggressive.

Your situation sounds different, but maybe leashing would help. You shouldn't tolerate any aggression.

I also like the idea of distracting him with a trade.