Hello, I'm Dr. Deb. I'll do my best to help you today.
I'm so sorry that you're having this problem with your new pup.
This is obviously a really tough situation since clearly she doesn't have many reserves if she's so thin.
Hopefully, you'll be able to get her through the weekend and the following are my suggestions towards that goal:
1. Internal parasites are a common cause of gastrointestinal issues in young pups. If you have a local grain or pet store open today, I'd purchase Pyrantal Paoate and worm her for round worms, the most common cause of parasites in pups.
The dosage amount will be indicated on the label.
2. Over the counter Pepcid AC can be given which may help with her nausea issues. The dose is 1/4th mg per pound of body weight twice a day.
3. I'd purchase Pedialyte and syringe feed her only small amounts at one time. If she's really nauseous, then larger amounts may stimulate her to vomit.
4. I typically advise withholding food for 24 hours but I'm concerned about that length of time for her. So, if she hasn't vomited in 4-5 hours, offer her a bland diet of chicken
and rice. If she doesn't want it, then you could offer her human baby food (avoid those with onion or garlic in them). You could also mix it with pedialyte in a blender and use your syringe to feed small amounts to her at one time.
(low blood sugar) is also a concern if she's really small and young. I'd rub pancake syrup or honey on her gums every 2-3 hours to keep up her blood sugar.
I would continue to isolate her from your other dogs on the off chance that she might have something contagious.
I hope this helps and that this will enough to get her through the weekend. Deb