Three young female camels were subjected to an eleven day period of dehydration followed by a single large drink. Blood haematocrit and plasma protein concentration were monitored regularly during dehydration and for 48 h following watering. Blood samples were taken at regular intervals, before and after watering, and prepared for scanning electron microscopy (SEM) for analysis of red cell size and shape. Plasma protein concentration did not change rapidly on watering implying that the camel has homeostatic mechanisms which regulate plasma osmolarity by controlling the rate at which large volumes of water are absorbed on drinking. By SEM, camel red cells were elliptical in shape with mean surface dimensions of 6.5 microns x 4.0 microns with an estimated minimum thickness at mid point of 0.95 microns: neither their shape constant nor size changed on dehydration or watering corroborating the absence of major and rapid changes in osmolarity.