Quantifying maternal antibody transfer to colostrum and cord blood reveals virus-specific selectivity in dogs

Abstract

BackgroundNeonatal infections are a leading cause of mortality in dogs, with up to 30% of puppies dying within the first three weeks of life. During this period of immune development, protection is highly dependent on maternal antibodies (MatAbs) transferred across the placenta and via colostrum. Despite the critical importance of this transfer, little is known about the biological or clinical factors that determine its magnitude, whether specific antibodies are preferentially transferred, or how these processes vary across a broad population of dogs. MethodsTo quantify and explore the determinants of MatAb transfer in dogs, we analyzed matched maternal serum, cord blood, and colostrum samples collected from 44 client-owned dams undergoing cesarean section at a university veterinary hospital. Total IgG and virus-specific antibodies against canine parvovirus (CPV) and canine distemper virus (CDV) were analyzed. We also evaluated the influence of maternal factors, including age, breed, body weight, parity and litter size on MatAb transfer efficiency. ResultsAcross this diverse population, we observed limited transplacental transfer of MatAbs (4.5-6% maternal titer), in agreement with previous studies and as expected with the endotheliochorial placenta of dogs. In contrast, virus-specific IgG was highly enriched in colostrum, with 10.7-fold (CPV) and 8.1-fold (CDV) increases relative to serum. Transfer efficiency was significantly greater for virus-specific antibodies than for total IgG (3.2-fold), suggesting selective enrichment of antiviral antibodies during colostrogenesis. Maternal serum antibody titer emerged as the primary factor influencing the efficiency of antibody transfer. ConclusionsThese findings provide the most comprehensive quantification to date of MatAb transfer routes in dogs, revealing preferential transfer of virus-specific IgG to colostrum and highlighting the crucial role of colostrum intake for neonatal immunity. This work establishes a foundation for identifying antibody characteristics that influence MatAb transfer efficiency and reiterates the importance of ensuring dams have adequate titers of virus-specific IgG prior to breeding.