new puppy and older Shih Tzu

Question
Dear Dr. Connor,

In August, my husband and I adopted our 9 yo Shih Tzu from a high kill shelter. He is as sweet as can be, lovable, cuddly, and more playful than a lot of 9 yo dogs. He was ok on his own, but also ok with some other dogs, so we decided to go ahead and add to our family a new member... a 3-4 month old female Shih Tzu from a rescue.

Our new puppy is also sweet, but she is teething and looks at our older dog's tail as the most interesting of chew toys. In the beginning, our first adoptee just ran up onto our couch and did not address the puppy's behavior at all. Now that puppy has gotten taller and can nip at him while he is on the couch, he tries to 'warn' her to back off by barking and parenting nips (he does not bite her).

Our new puppy has been with our family for 3 weeks now and although there has been some progress, we are wondering if this is a natural pace and if we should do anything differently. When they bark at each other, we try to just let it happen so they can work it out, but this evening my husband had the 9 yo dog on his lap when the puppy approached. They started barking at each other, so my husband went to move the dog off of his lap to avoid accidently getting bit. At that time, he turned around and gave him a warning nip that bruised his skin.

What can we do to train the pup not to nip at the older dog's tail? Should we play with them separately until she grows out of her first teething stage?

Also, is there anything we can do to help our elder canine to adjust to our new addition better? We shower him with affection and try to always acknowledge him first. What else can we do?

Thank you in advance for your help!

Answer
It appears to me (from your description) that your older dog is behaving normally toward this puppy (who is very annoying lol.)  the thing that bothers ME is the "inadvertent nip" your husband received!  It appears that your older dog is trophying your husband and this may escalate to the point where he will not allow the younger dog to approach either one of you when he is in your lap or on the furniture..  NO NIP is acceptable, absolutely none.

Observe the older dog's interaction with the puppy as you have been; your older dog is making a statement of rank to that puppy but this should NEVER escalate to blood letting of any sort.  The puppy will learn to respect the older dog's "space" and the older dog should learn to tolerate the puppy (to a point).  HOWEVER, any sort of aggression (barking, growling, etc.) from the older dog toward the puppy when the older dog is ON THE FURNITURE or IN YOUR LAP should get an immediate reaction from YOU: Stand up (if he's on your lap) and walk away; if he's sitting near you, turn toward him with a growly "nah!" and then get up and turn your back to him.  Feeding the older dog first, letting him in/out first, etc. is all well and good, but it appears to me this dog has gotten a bit of a wrong idea about who HE IS in your household.  Make him work for things: ask him to 'sit' for treats, for meals AND for being allowed on the furniture.  Routinely tell him "off" if he's on your lap and move away from him.  Establish some psychological dominance here to be certain he understands he is not in control.  Please repost in a week or two with update.