We just got a new puppy from the shelter, and she was a happy, playful dog for the first day. The second day, she started puking, not eating or drinking and hardly moving. We took her to the vet, and after 2 days there we took her home. They said she was acting fine, and gave us some meds and special food for her. As soon as we got her home, it started again. And we found out that 3 other dogs in her litter have the same symptoms. Parvo test was negative, but what else can it be? The vet just gives her fluids and sends her home, to start the same thing over again, and deplete my pocketbook. Should I change vets? Should the shelter be responsible? Please help!

Would the shelter be willing to get in contact with the other adopters (I am assuming that the littermates have been adopted out) and give them your phone #? THat way you could all compare notes and see if anything is working better on one of the pups.
Its possibly coronavirus, which has pretty much the same symptoms as parvo, or it could be a GI parasite like Giardia or Coccidia, which are hard to find in fecal tests.
Unfortunately, sometimes all you can do is treat the symptoms, and keeping the pup hydrated is number one priority. I hope she starts to come around soon.

I'm going to do some guessing based on my troubleshooting experiences.

Know:
Pup Ok at Vet, but not at home.
Puking - not good (something ingested?)

Water bowl, food bowl? Switch to glass.
Water? Switch to bottled.

Something that she is chewing. A toy, the rug with a pesticide on it?

Any people food? Some people food is toxic. Go to no people food.

Treats? Alergic to an ingredient?

Is she eating anything outside, like a posonous bush?