First of all, we are not Vets. Are there any other symptoms, panting, pacing, bloating? How many times has she done this? Any chance she got into anything? Has she been eating grass? This could be nothing more then a stomach upset. It could be something more serious and, I am afraid if you gave the Pepto, it may mask symptoms. I would withhold food but make sure she is drinking water and not throwing that up. Keep an eye on her for worsening symptoms or if she seems anxious or distressed. If so, your Vet Should probably check her.