Hi,
I have two twelve year old Border Collies (Max and Annie). I recently adopted three puppies, a Yorkie (Cocoa), a Chinwa (Leo) and a Chihuahua (Pablo). The pups are all around ten months old now. The collies will tolerate the small ones, but since the collies are a bit elderly they get a little annoyed at the pups and will growl at them if they get too close. The Yorkie in particular loves to jump up at Max's face to lick his mouth. He doesn't like it one bit, but the most he will do is give her a warning growl, and she will back off.
Now that we have had them all together for a few months they all just seem to go about their business. The older dogs more or less ignore the pups.
The collies love to run and play fetch. Its so much fun to watch the little ones try to keep up with them!
It seems to me that puppies seem to eventually learn their boundaries with older dogs, however it might take some time.
Hope this helps
Cocoa's Mom