Abstract
Haemograms were determined for 90 Mystromys, 3-24 months of age, to establish normal values and to evaluate the influence of age and gender. Males over 6 months of age had higher red blood cell counts, packed cell volumes and haemoglobin levels than females of the same age. The haemograms of females 3-5 months old resembled those of males. Age and gender did not cause detectable differences in leucocyte numbers in animals over 6 months old.