HELP

Question
QUESTION: I have a 4 year old yorkie/chihahua (LoBo)neutered male dog. He was raised for 2 years with a great dane. The great dane passed away and we only had the yorkie/chihahua by himself for 2 years. I just recently (4 weeks ago) got a toy poodle puppy. Now he is 12 weeks. I did the wrong thing by the way we introduced them. I realize that after I read the internet. LoBo pouted for a couple weeks, wouldn't hardly eat, moped around etc. But then he and the puppy would play, chase each other and wrestle around. I crate the pup at night. LoBo sleeps with us. My husband constantly loves on LoBo and I always show him attention first when I come home from work, loving on him etc. then the puppy. This past Saturday LoBo really attacked the pup...grabbed him and started shaking him. I got LoBo off of him and scolded him however, the pup yelped and cried. Of course I had to pick him up to see if he was hurt. There was no sign of blood. I thought maybe LoBo was asleep and the pup startled him...LoBo has NEVER acted aggresive before. Then today my husband was home with the dogs and said they were fine all day. I came home, same routine except both dogs met me at the door. I petted and loved on both this time. Just a little later LoBo was sitting next to me on the floor and Gus was on the other side, I started to pet the pup and all of a sudden LoBo grabbed the pup and started shaking him. I am at wits end. I SO LOVE THEM BOTH. What am I doing wrong and what can I do. I don't want to get rid of either one. I don't want LoBo to hurt him. PLEASE help me.....
Will LoBo EVER accept him?
Sincerely,
Kathi

ANSWER: Don't beat up on yourself too much for the introduction.  I know the neutral territory and all that is the conventional wisdom, but much of the ''conventional wisdom'' is just something somebody decided sounded good with no evidence to back it.  Often it is dead wrong.  So it may or may not have helped.  

Can you fix the problem?  The attention you are giving LoBo is good.  You may also need to give him better leadership.  You are top dpg. and as such, you have the right to bring a new puppy into the house.  Having a good pack structure reduces such problems. The dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/

You may need to watch the puppy too.  As it adjusts to its new home and matures, it may be now challenging LoBo for leadership.  Such things can be hard to pick up, body position, who sniffs the others butt first, etc.  

See how things go.  Continue to crate the puppy at night and anytime you can't keep a eye on them.  I hope you can work this out.  It is most common with 2 females, but sometimes there is no making 2 dogs get along.  In the end, you may have to rehome the one.  

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

QUESTION: Thank you for responding so quickly...didn't want to hear the last part tho where some dogs just don't get a long and "may have to rehome the one." How do you pick? The older one that has been in your life for 4 years and it would be like "winning" not wanting another dog in. The pup who is so loving and seems will be a good dog and I am sooo attached to already. How long do I give them until the pup is 6 months? One other question, is it terrible to muzzle the older dog when they are together until the pup is older?
Kathi

Answer
I don't think muzzling the older dog until the puppy grows up is the solution.  He will only resent it and wait for his chance.  

You really must teach LoBo that you are in charge, and won't stand for aggression towards the puppy.  The 2 may never become very friendly, but could learn to tolerate each other.  

Talk to vet about neutering the puppy.  Some vets are now doing it before the traditional 6 months.