Can't say precisely how many sheds before his scales look right again. I'm afraid you'll just have to be patient... & be even more progressive- next...
I booked an appointment for Monday so we will see what happens in the meantime. This particular supplier keeps the rats in drawers in racks and it's...
Probably something she ate. Live rats can carry (& share) internal parasites ("worms" & various pathogens), so maybe it's time to find a better food...