My pastel enchi boy did the same thing around the same weight. Gave him a nice, smelly mouse and he decided eating was good again. Back to pounding rats now. I've found a mouse or two helps when mine go off food. Pretty sure it's the increased smell... Never realized how much difference there was until I started thawing rats out when I got bps. I can smell it when I'm thawing mice but the rats are pretty much odorless to me.