Abstract

The passive transfer of immunoglobulins is considered a crucial component of cetacean neonatal health.¹ Animals with similar placentation as cetaceans demonstrate predominant transfer of immunoglobulin G (IgG) in the post-parturient period.^2-5 Failure of passive transfer (FPT) of IgG can predispose neonates to life-threatening infections. Therefore, early identification of passive transfer status should help reduce neonatal morbidity and mortality. While widely used in exotic and domestic hoofstock and swine species, rapid and accurate conventional immunoglobulin tests for determining passive transfer status have not been validated in dolphins.^6-9 In this study, we evaluated the glutaraldehyde coagulation test and the Ig Immunocrit technique for the purposes of rapidly identifying FPT in dolphin calves. Previously reported IgG concentrations in calves surviving beyond their first year were used to establish the following equation to calculate expected age-based IgG concentration for healthy calves less than 1 year of age: IgG = 906 + (39.764 x age in days) µg/mL.¹⁰ Failure of passive transfer was defined as calves exhibiting IgG concentrations ≤906 µg/mL at day 0. Serum samples used in this study were from dolphins less than 1 year of age (n_serum=177; n_calves=38). Fifty-eight samples were from dolphin neonates under 30 days of age. Linear correlation between serum IgG and pool-side assays showed the glutaraldehyde coagulation test was a more reliable predictor of failure of passive transfer status in dolphin calves. Additionally, hemolysis appeared to affect accuracy of pool-side tests in estimating IgG. The glutaraldehyde coagulation test, therefore, may be a useful tool for the rapid diagnosis of failure of passive transfer in neonatal bottlenose dolphins.

Acknowledgements

The authors would like to thank the trainers, veterinary technicians, and veterinarians of the MMP and SeaWorld Parks & Entertainment for their assistance with the treatment and care of the animals. A special thanks to Kevin Carlin, Cynthia Smith, Marcie Oliva, Scott Citino, Jessica Emerson, and Meg Sutherland-Smith for their professional advice and assistance on this project. Funding for this project was provided by the U.S. Navy Marine Mammal Program.

* Presenting author

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