Neonatal mortality within 3 weeks of birth is highly prevalent in puppies (17%–26%) and has not been well studied. Puppies are born with few to no gammaglobulins, and adequate passive immune transfer through colostrum intake is a key component affecting neonatal mortality. Quality of passive immune transfer is evaluated by measuring concentration of immunoglobulin G (IgG) in neonatal blood. In puppies, IgG absorption at 4 hours of life is decreased 2-fold compared with absorption at birth, decreasing to nearly nothing at 12–16 hours.
IgG concentrations 2 days after birth were measured in 149 puppies from 34 litters; levels correlated significantly with weight gain. Seventy randomly selected puppies were supplemented orally with hyperimmunized adult plasma twice within the first 8 hours of life. A minimal IgG concentration at or below 230 mg/dL was associated with a significant increase in mortality. Puppy IgG concentration was significantly correlated with growth rate but not with breed size, sex, supplementation, litter size, or colostrum IgG concentration. Oral IgG supplementation with hyperimmune plasma did not decrease risk for mortality or improve serum IgG concentration at 2 days of age. This study demonstrated an association between neonatal mortality and passive immune transfer. Because no alternative source of immunoglobulins has proven to be effective, attention must be paid to colostrum intake within the first 12 hours of life.