Pistachios could upset her stomach.
I would try to settle her stomach with pepto bismol plus pepcid ac. The pepto bismal soothes the stomach and the Pepcid ac reduces the acid in the stomach.
1/3 of a pepto tablet, or 1 teaspoon of pepto, per each 10 pounds of dog.
1/4 of a Pepcid ac tablet per 15 pound of dog.
You can give them together and repeat the doses every 8 hours.
Only let her have small amounts of water. If she drinks too much at once, she may vomit again. You can also give her pedialyte children's drink for hydration. She will not drink it so you have to give it with a syringe or eye dropper.
To help keep her blood sugar up, while she is not eating, you can put a spoonful of pancake syrup, or honey, in her mouth every few hours.
When she has not vomited for 8 hours, offer her one bite of a bland diet of plain cooked chicken breast and white rice. Wait an hour, to make sure she is not going to vomit, before gradually giving her more. So if you give the one bite, and she vomits, then she needs to see a vet. The most likely cause would be gastroenteritis which means inflammation of the stomach and intestines. It can happen when they eat something new, with stress, with drinking out of standing water outside, or putting unusual things in their mouths. We treat it with an antibiotic called "metronidazole."
So if she is not better by tomorrow, she needs to see the vet.
I hope this helps.
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