You must find a vet familiar with potbelly pigs as they have needs very different than the domestic swine raised for meat. You can google a list of those vets with specialized training. You would not have your diabetes treated by a surgeon so you must do right by your potbelly, an animal that has NOT been bred over a period of a hundred years to produce the most meat in the shortest period of time with the worst quality food.
Potbelly pigs are essentially wild animals that happen to be friendly with humans and we must treat them with the respect they deserve. We must treat them in the same way that they lived in the jungles of South East Asia with their unique metabolism and nutritional needs.