Circulating Immunoglobulin G in a Healthy Population of Neonatal Bottlenose Dolphins (Tursiops truncatus)
Abstract
The passive transfer of immunoglobulins is considered a crucial component of cetacean neonatal health.7 Like the bovid, equid, and suid families, the cetacean family has epitheliochorial placentation which prevents transfer of immunoglobulins from the dam to the fetus in utero.3,9-11 The predominant immunoglobulin in colostrum from animals with this type of placentation is immunoglobulin G (IgG).1,2,6,8 Failure of passive transfer (FPT) of IgG can, therefore, predispose cetacean neonates to life-threatening infections. Dolphin calves with FPT require immediate and intensive veterinary care to help increase chance of survival. Early identification of passive transfer status is critical in reducing morbidity and mortality in neonates. No assay for the fast identification of successful passive transfer in bottlenose dolphins currently exists.
In this study 79 serum samples (collected between 2002 and 2009) from six Navy bottlenose dolphin calves were used to establish normal IgG reference intervals for calves 0–48-hours and >7-days to 1-year-old using a custom quantitative bio-layer interferometry assaya.5 There was a significant, positive linear association between calf age and IgG levels (p<0.0001, R2=0.73). Predicted IgG levels for healthy calves in this population may be calculated using the following equation: IgG = 906 (39.764 x age in days). IgG reference intervals for calves 0–48 hours (n=8) and >7-days to 1-year-old (n=69) were 62–406 and 1,303–5,550 µg/ml, respectively. These newly established reference intervals can aid in standardizing and validating rapid, pool-side tests to identify FPT in neonatal bottlenose dolphins.
aOctet QKe System, FortéBio, a division of Pall Life Sciences, Pall Corporation
Acknowledgements
The authors would like to thank the trainers, veterinary technicians, and veterinarians at the Navy Marine Mammal Program, including the U.S. Army animal care specialists, for their assistance with the treatment and care of the animals. A special thanks to Cynthia Smith, Linda Archer, Jim Wellehan, Jennifer McGee, Chris Dold, and Meg Sutherland-Smith for their professional advice and assistance. Funding for this project was provided by the US Navy Marine Mammal Program through the National Academy of Sciences, National Research Council.
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