if he has been fixed the lack of hormones can often cause that, it's hard to keep a dog's weight down after so, they tend to blout out a bit if not on a strict diet.
sherman still has his nads intact, dunno what could be worse tho, having your nads popped or being a 70 year old virgin.
btw i was mistaken he is 10 now, and getting the grey muzzle and all.
still when at the no-leash park, he'll spend a few hours with full afterburners on trying to probe anything with a rear entrance.