I havent had any of mine that were off feed that long but, one of my females quit eating this winter and refused for 5wks. (nothing about her husbandry has changed and she ate for months every week with no prob). Anyway I dropped a african soft furred rat in her enclosure and BAM! Now she is back to small rats every week no prob. Maybe trying a different food source will get his appitite going again. Only problem is you want to be able to get this new food source all the time if he decides that thats all he will eat.

Just a thought.

Good Luck.