Role of amniotic fluid in newborn acceptance and bonding in canines

Maternal behavior, such as licking and cleaning of the newborn, and oral consumption of the placenta and membranes is characteristic of nearly all mammals. They are the first step toward maternal acceptance and bonding in canines. Factors affecting these initial behaviors are unclear. Also the impact of these initial behaviors in regard to establishing long-term newborn acceptance and bonding is unclear. We undertook this study to determine the role of the amniotic fluid on newborns and oral consumption of the placenta and membranes on the initial development of the maternal-newborn relationship. Thirty litters were studied, nine serving as controls in which the maternal and neonatal behaviors were simply observed for 36 h after delivery. Twenty-one litters underwent three different manipulations and served as the study groups. The first study group consisted of nine litters where the pups, placenta, and membranes were immediately separated from the mother at birth. Pups were washed three times and returned to the mother, and observation began. The second group of nine litters had the pups, placentas, and membranes immediately removed from the mother at birth. These pups were washed three times and returned to their mother. After 2.5 h of observations, pups were bathed in their amniotic fluid and the placenta and membranes returned to mother. In the third study group, three litters had the pups immediately separated from their mother, washed only once, and returned to their mother. The placenta and membranes were removed permanently in this case. In the control group, acceptance of pups was universal. In the first study group, all pups were rejected for the entire 36 h of observation. In the second study group, all pups were rejected until they were bathed in amniotic fluid and the placentas returned to the mother. At this point, the mother accepted all pups. In the third study group, all pups were accepted by the mother during the entire observation period. It appears that having the amniotic fluid on pups is an important signal for the mother to begin licking, accepting, and establishing maternal bonding with the newborn in canines. In the absence of amniotic fluid on the pups, rejection for the first 36 h was universally present.