I have used Cerenia pills with Zoe....worked wonders! She was vomitting and had diarrhea....she got an injection of Cerenia and I came home with 4 pills (4mg each) to give her 1 per day. The injection and pills last 24 hours. While on the cerenia, Zoe's tummy calmed down and the nausea went away, she was able to eat and to keep down everything she ate.....I would try talking to your vet again.....it was almost a miracle for Zoe.