Here's a link to the thread I started when I had to deal with my issue. Anne (myprecious pups) posted there about her baby, too.
http://www.yorkietalk.com/forums/bre...yone-help.html
I realize that we're not talking about the same exact problem, but what is common to them is that all these babies had rear leg issues. Regardless of the exact diagnosis, it is critical to do all you can quickly. If left untreated, you may have a baby crippled for life.