answer:Go to a different vet. Have them run some bloodwork and take x-rays. Go immediately. If the regular vets are closed, find an emergency clinic. You don’t mention if there are any other symptoms. If there is no vomiting (or attempted vomiting), it’s unlikely to be gastric dilatory volvulous (bloat), inteseception, or obstruction. If there is no coughing, exercise intolerance or tachypnia, it’s unlikely to be heart failure. Ascites as the result of liver failure is also a concern. Almost every possible cause of a painful, distended abdomen is a serious medical concern.