Is it her BUN that's 130?
There are many things that can make a BUN go up like that. Some pups aren't "put together right" and are born with bad kidneys. Others get into something toxic and that can damage their kidneys. Others get a bacterial infection (pyelonephritis). This can happen secondary to untreated kidney stones.
I think you should talk to the vet about what they mean by not being optimistic. Kidney problems are extremely serious, and yes, her life is in danger just from the continued vomiting/probable dehydration alone.
They gave her fluids to help her stay hydrated and to help her kidneys continue to function. Did they start her on antibiotics? Offer to hospitalize? Her best chance at getting through this is to go to a specialist.
I'm sorry.
