Abstract

Cold-stress syndrome is a leading natural cause of mortality in free-ranging Florida manatees (Trichechus manatus latirostris). Comprehensive investigations into clinicopathological derangements and identification of prognostic indicators in cold-stressed (CS) manatees are limited.^1,2 The objectives of this study were to 1) compare admission blood analyte data of survivor manatees to their pre-release data after rehabilitation, 2) identify blood analyte prognostic indicators for survival, and 3) summarize pathologic changes in CS manatees that died during the study period for correlation with clinicopathological findings. CS manatees admitted to a rehabilitation facility between 2007–2017 were included: 63 manatees with data for clinicopathological analysis (7 non-survivors and 56 survivors) and 14 manatees with necropsy data. Admission and prerelease data were compared using a Wilcoxon sign rank test, and prognostic indicators examined using the Wilcoxon rank sum test and receiver-operating characteristic curve analysis. Main interpretive clinicopathological findings indicated systemic inflammation, bone marrow damage, diuresis, malnutrition, tissue necrosis, fat mobilization, hepatic impairment, acid-base imbalances, and gastrointestinal ulceration.^3-10 The best performing prognostic indicators for survival included: platelets, aspartate aminotransferase, calcium, and BUN. Main anatomic pathologic findings were cutaneous lesions (n=14), lipid depletion (n=11), upper gastrointestinal ulceration and/or hemorrhage (n=9), and pneumonia (n=7). Based on our study findings tissue injury, gastrointestinal ulceration, and hemodynamic and platelet derangements are major factors involved in mortality of CS manatees. These results contribute to the understanding of the complex CS syndrome pathophysiology and provide a clinically applicable tool for improvements in the medical care of manatees.

Acknowledgements

The authors wish to thank the Florida Fish and Wildlife Conservation Commission and SeaWorld Orlando for their contributions to this project and their valiant efforts in cold-stressed manatee rehabilitation and conservation. The authors are grateful to anatomic pathologists involved in reviewing histopathology samples utilized in this study.

*Presenting author
+Student presenter

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