We have adopted a fox faced pom and she is a delight! But we have taken her on three weekend overnights and each time we get back she is sick with loose BMs and begins throwing up. The first few times we tested her for everything and it was always negative. She eats the same food while we are gone and she doesn't get outside much when we're gone so I would doubt it was a reaction to something. She is still eating and drinking but nothing seems to stay down...any suggestions?