Hi,
I just got a yorkie about 1 1/2 weeks ago. I have a Golden Retriever that plays with the puppy & I have a Pekingese mix who does not like him. Pookie is 10 weeks old & sounds just like your pup - he's a wild man for a couple hours & then he goes to sleep. The Peke growls, barks & snaps at Pookie
People tell me it takes time & hopefully they will be OK. We supervise so nobody gets hurt. The Golden's tail thumping & wagging is a big attractant for Pookie. We have to "remove" him & tell him "no" & give him toys instead. Hopefully they will all be buds soon.
Happy Holidays,
Sherry B