It's what dogs do - especially terriers. You can try to redirect him and give him other toys but usually only separating them for toy play can stop this. A highly trained dog will drop the toy and back off when you say "Leave It", but unless you want to train to that level, there isn't much to do besides crating the other dog, letting him outside or putting him in another room. That is part of owning more than one dog - finding ways for them to eat, play with toys and chew in peace - and it can be hard work when at least one of them is feisty!
To a dog, a toy or chewie is viewed as a resource and like food, they are never going to willingly share.
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |