I thought I would let you all know that while he appeared to be getting stronger we went out two mornings ago to find him unresponsive so we let him go over the rainbow bridge. Thanks to all who offered advice and suggestions!
Sorry for your loss. It's always the pretty ones that break our hearts.
I would refrigerate his body, and contact the state agriculture department to get a necropsy done. Some are free, some cost, but not very much. You really should find out what caused his death, to know what you may be dealing with.