Hello, I have never posted here before and am mostly just posting anywhere seeking help about this problem with my two dogs.
Anyway, we have a puppy Lhasa-Poo, who is also a runt, not even a year old yet (though getting close) and an older dog who is about 6 or 7ish I think, he is a Lhasa-Bichon.
Basically my puppy likes to bite my other dog. HARD. To the point of yelping usually. And it has not improved at ALL! I was hoping she would start to grow out of it but it doesn't seem that way. And our other dog is...well, a wuss.

He doesn't knock her off or bite back (I don't want them to bite each other, but I thought if he did it just once maybe she would stop), he just runs...usually to me and the rest of my family.
She never lets up no matter how hard we try to stop her and chases him around almost every day (which would be fine if she didn't bite so hard). As a result my older dog barely plays at all anymore when he used to play everyday. He can't even run around in the yard without her going after him; forcing him to stop.
Any ideas on what to do about this?
They do have some moments of sweetness together, but they are few and far between.