My yorkie is sick

my yorkie has a gastrointestinal infection, after I switched her food she started vomiting, diarrhea, then black tarry stools.  The vet checked her and took exrays and blood tests, her tests were all ok I took her home and a few hrs later she spiked a 104.6 temp took her back to the vet and was told the infection seemed to be spreading into the rest of her. They arent sure why maybe a small tear in the lining of her stomach or intestines they think she has an ulcer and colitis. Yesterday she would eat a little and drink today she wont eat but she will drink a little.  Is she getting worse or is this normal process?

[ginger899]

I am sorry I don't know the process of this kind of problem, so am not much use to you as far as that is concerned.
But I do know that Slippery Elm herb may help her. You will need to ask your vet of course, first. Slippery Elm is OK for dogs. It won't cure the infection, but it will help the stomach and intestinal lining, 'coat' it, protect it, and help it to heal.
I would say that it is probably quite natural at this stage that she can't eat very much. She needs fluids though, and may very well be able to tolerate bland chicken broth made with chicken breast,   (basically, the water that chicken has boiled in)or some low-salt, onion-free canned chicken soup.
I wouldn't use baby foods, store bought, as they can contain onion powder.
I do hope the infection is cleared quickly, and your girl is OK soon.