Abstract
Serum amyloid A (SAA) facilitates an important role in the innate immune response relaying the inflammatory cascade from cytokines to leukocytes. In horses, calves, and manatees, SAA has shown greater diagnostic accuracy in the detection of subclinical inflammation than classically used biochemistry and complete blood count values.1-5 Expression of SAA in bottlenose dolphins has been evaluated in free-ranging animals and those under human care.6-9 The purpose of this retrospective study was to establish a SAA reference interval for a healthy population of dolphins under the care of the MMP and to compare SAA in dolphins with respiratory disease to the healthy reference interval as well as to other traditional markers of inflammation. A dolphin SAA-specific ELISA was used for this study. Reference intervals for healthy MMP dolphins (n=30) were 1.2–4.0 mg/L (25–75th quantile) and 0.91–5.2 mg/L (10–90th quantile). The healthy control group had a significantly lower mean SAA than the case group (n=14) at the onset of clinical signs of respiratory disease (3±2 and 71±94 mg/L, respectively; p<0.006). Stepwise regression models were used to identify which of the following inflammatory markers best predicted illness onset and resolution: WBC count, neutrophils, eosinophils, lymphocytes, ESR, ALP, iron, total protein, albumin, A/G ratio, globulin fractions, haptoglobin, pre-albumin and SAA. Of these, SAA and iron were the most sensitive indicators of onset and resolution of respiratory disease. Quantitation of SAA may, therefore, provide the clinician with greater insight into the onset and resolution of respiratory infections and inflammation in bottlenose dolphins.
Acknowledgements
The authors would like to thank the IAAAM Medway Scholarship Fund and the MMP for supporting this project. The authors would also like to thank those who provided assistance with sampling, analyses, and data collection, especially Celeste Benham and Brittany Novick from NMMF, and all the veterinary and training staff of the MMP, as well as the staff of the University of Miami Acute Phase Protein Laboratory.
* Presenting author
+ Student presenter
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