Does Placental Efficiency and Vascularization Affect Puppy Health? A Study in Boxer and Dobermann Dogs

Background: The anatomical and functional characteristics of the placenta influence the
adaptive ability of the fetus to the extrauterine environment. Placental efficiency, measured as the
gram of neonate produced by each gram of placenta, summarizes these characteristics. In the present
study, placental efficiency and its impact on the 7-day postpartum life of the puppies were studied
in canine large breeds. Methods: Placental efficiency (PE) was computed using chorioallantois
weight (WPE) and surface (SPE) efficiency for puppies born from natural delivery or elective cesarean
section. Capillary density was also histologically determined. Neonate viability was estimated by the
APGAR score and the daily weight gain (DWG) was recorded on day 7 after delivery. Results: from
15 large-breed bitches, 69 live puppies were born by natural delivery (24 puppies) and elective
cesarean section (45 puppies). Cluster analysis detected a group of neonates for which reduced
placental efficiency (8 for the WPE, 9 for the SPE) was identified, despite a placental weight and
surface within the mean and no difference in capillary density. In this group, the DWG was lower
and the mortality within 7 days was higher. Conclusions: the results suggest that placental efficiency could be an additional tool for the evaluation of a puppy in the first 7 days after delivery.