Shih-tzu agression

Question
QUESTION: My aunt was ill and needed someone to take her 2 year old neutered male shih-tzu off her hands. I volunteered thinking that he would keep my miniature schnauzer company while I was away at work. This shih-tzu Cosmo seems to have major aggression, he attacks his chew toys and will bite me if I try to take them from him.  He will also bite me if I try to remove him from a piece of furniture.  At first he and my Chewy (miniature schnauzer) got along fine, but now most of the time they fight. I have resorted to putting them in separate rooms during the day, but even when I am home the new Shih-tzu insist on growling and biting my miniature schnauzer to the point he is retreating to high grounds where Cosmo can't reach him.  I have recently found out that I am the fourth home that this shih-tzu has had and I am trying really hard to keep him, but it is difficult because I can't even groom him because he bites and I can't take him to be groomed because he bites them as well.  He can be really sweet, but only if I do what he wants me to. I understand that he is trying to show me that he is dominant but what do I do?  I tried a stern voice and I have even tried popping him with a rolled up newspaper in which he grabs and rips to shreds in rage! Can you please give me any advice on getting him to behave? Is my only option to give him away?  I feel like my miniature schnauzer is suffering in this situation, he has to be separated to eat or he doesn't even get to eat! they sometimes play happily but most of the time not.  Any advice is appreciated. Thanks Melissa

ANSWER: Hi Melissa,

Your choices are simple:
1. Rehome him where he is the only dog and no rolled up newspapers.
2. Give him back to your aunt
3. Try and find a breed specific rescue to foster him.

None of the above are easy. But clearly this is not the right situation for any of you. Sorry I do not have better things to say. I hope all goes well.

---------- FOLLOW-UP ----------

QUESTION: I appreciate your response. I really don't want to rehome him since this is already his fourth home.  My aunt cannot take him because she is in and out of the hospital frequently.  Is there any hope that his behavior will change?  Sometimes he and my miniature schnauzer lie around together happily and other times not so much. I have noticed that at bed time if one of them gets on the bed the other gets off and they will not sleep together.  
Would obedience classes help?  I really want both of my boys to be happy.

Answer
The dog aggression is only part of the problem, he also targets humans, it's most likely why he is on his fourth home sad to say. All dogs are good when nothing is going on! It's there responses to stressors that is the problem here.

Why not try to have someone who specializes in aggression come out and assess in person? Try www.ccpdt.com Group classes may help but it's not in home-that would probably be most realistic.