Hi everyone my name is Sofy and i'm new to the site. So glad i found a place where i can hopefully find answers to our questions.
My husband and I have a 6 month old female Rat Terrier, her name is Daisy but we call her Bugs or Buggy. At the moment she is EXTREMELY sick and we don't know what to do

Since this morning she has been:
Vomiting (it looks like saliva or acids)
Diarreah but it's practically pure blood
Lethargic, she doesn't even look up at us and can barely walk
Not eating or drinking
We already took her to the vet and they tested her for Parvo, it was neg. The vet pretty much just gave us antibiotics and an IV to administer and told us " It could be anything...maybe something she ate, so all i can do is give her Antibiotics and wait for the lab results" (blood tests)
Our baby is literarly on the verge of dying and at this point we don't think she'll make it through the night. We don't know what to do! Has anyone ever experienced something like this with their dog? Any suggestions on what it could be? She's going every 30 minutes and it's pure blood. Thank you in advance for your help.