Of course, there will be water in the fat and quite a bit is used when they metabolize the fat.  When the fat in their humps is used up, they’ll shrink down and get all floppy.

They can go up to 8 weeks without water in winter.   One of the tricks camels picked up in order to not use the water in their bodies as often is infrequent urination.  They can sometimes even recycle the urine instead of expelling it and, when they do, it’s concentrated.  Lovely, no, interesting, sort of.