40 pounds lighter. Or, should be all bones and ribs. Virtually no fat. Unfortunately, it will take 1-2 months to get off that much blubber. Work up to at least 3 miles a day.
Swimming is the best exercise of all.
Try to get him swimming every day. Listen to his limits but also push him a bit. One adult tablet 1-2 times a day as needed. Give with bite of food. Give 3-4 cloves a day or equiv.