There is a big difference between lethargic and laid back. I don't have pygoras, but I do have a few nigoras. They're little bundles of energy, they hardly ever stop bouncing.
Asking questions for more information. How do his eyelids and gums look, white, pink, or red? Is his rumen rumbling, is he burping, or is he bloated? What have you given him to eat? Does he have hay available? Could he have gorged himself on grain? Have you taken his temperature, and if so, what is it? If you haven't taken his temperature, do so asap. Does he have any diarrhea? Any coughing, sneezing, runny nose or eyes? Has he ever been wormed or given a coccidia preventive or treatment?
Is he willing to walk or stand, or does he refuse to get up (or wants to lay down as soon as you get him up).
Also, do you have a livestock vet you can call for advise? The internet or a forum does not replace someone who has spent years in livestock health.