It could be anything from parvo to a digestive problem. I hope your Vet dewormed her and you didn't use an over-the-counter wormer. Not to frighten you but my neighbor's died following over-the-counter worming. The same thing, of course, could have happened if she had used a prescription wormer but she'll never know.

Your dog needs to see a Vet - now.

No, nothing else to be done. The fact that the breeder gave the vaccines and/or wormed her doesn't mean he used prescription medication.

Take her to a Vet.

Just as a side note - why a breeder and not a rescue?