Development of iron deficiency anemia in infant rhesus macaques

Although previous research has documented the occurrence of an iron deficiency anemia in infant nonhuman primates, the temporal development of this condition has not been studied to our knowledge. We conducted a retrospective analysis of complete blood count data obtained from 56 rhesus macaque infants over a 5-month period. Fourteen infants were exclusively mother-reared, and 42 were nursery-reared. By 60 days of age, erythrocyte indices were lower in the mother-reared monkeys than in the nursery-reared animals. Between 90 to 150 days of age, an apparent iron deficiency anemia developed in the mother-reared infants only. This anemia was characterized as a microcytic, hypochromic anemia. The time of onset of this anemia was comparable developmentally to that observed in exclusively breast-fed human infants. At no time were these infants clinically or behaviorally affected by the anemia. Hematologic status of the mothers did not correlate with that of their infants. It could not be determined whether mother's parity was predictive of the development of anemia in the infant. These observed phenomena in rhesus monkeys may serve as a potential nonhuman primate model for the anemia that is observed in exclusively breast-fed human infants.