My senior cat has always had a tendency to vomit after eating, but now he is vomiting quite a lot. He was given a steroid (pred.) which has helped some. He is a very sensitive, nervous cat. His labs indicate that he does not have pancreatitis, and overall his lab work looks good. He had a full senior work up, as well as urinanalysis and the test for the pancreatitis (negative). He has been dehydrated, not eating well, nauseated and vomiting. Is the next step to do an ultrasound?