Neonatal deaths in bonnet monkeys born to dams with rudimentary papillae mammae

Deaths due to dehydration and starvation occurred in the early neonatal period in bonnet monkey (Macaca radiata) infants housed with their dams in an outdoor half-acre corral. Dams were found to have small, rudimentary papillae mammae of insufficient size to permit suckling. Both papillary and breast tissue of affected dams were histologically normal; the nipples differed macroscopically from those of normal females only in size. This abnormality accounted for half of the neonatal mortality experienced in this breeding colony over a 5-year period.