Clinicopathological prognostic indicators of survival and pathological findings in cold-stressed Florida manatees Trichechus manatus latirostris

Abstract

Cold-stress syndrome (CSS) is a leading natural cause of mortality in free-ranging Florida manatees Trichechus manatus latirostris, but comprehensive investigations into blood analyte derangements and prognostic indicators in CSS are lacking. The objectives of this study were to (1) compare admission blood analyte data of manatees pre and post rehabilitation for CSS to identify clinicopathological derangements, (2) identify blood analyte prognostic indicators for survival, and (3) correlate post-mortem anatomic pathological changes with clinicopathological findings to improve the understanding of CS pathophysiology. CSS manatees admitted to a rehabilitation facility between 2007 and 2017 were included: 59 manatees with data for clinicopathological analysis (7 non-survivors and 49 survivors) and 14 manatees with necropsy data (7 with and 7 without blood analyte data). Main interpretive clinicopathological findings indicated systemic inflammation, bone marrow damage, diuresis, malnutrition, tissue necrosis, fat mobilization, hepatic impairment, acid-base imbalances, and gastrointestinal ulceration. The best diagnostically performing prognostic indicators for survival included platelet concentration, aspartate aminotransferase, calcium, and blood urea nitrogen. The main anatomic pathological findings were cutaneous lesions (n = 14), lipid depletion (n = 12), upper gastrointestinal ulceration and/or hemorrhage (n = 9), and pneumonia (n = 5). Based on the identified blood prognostic indicators interpreted in the context of anatomic pathological findings, multi-organ tissue injury, gastrointestinal ulceration and/or hemorrhage, and hemodynamic and platelet derangements are the presumptive major factors of CSS manatee mortality. These results contribute to the understanding of the complex CSS pathophysiology and offer the use of blood analyte prognostic indicators as a clinically applicable tool for the medical care of manatees during rehabilitation, thereby contributing to increased rehabilitation success and conservation of the Florida manatee.

Cytochemical staining of leukocytes and platelets in the Florida manatee (Trichechus manatus latirostris): identification of a bilobed monocyte similar to other members of the Paenungulata

“…However, it is unknown if and how the proportions of these bilobed monocytes change with various diseases or clinical conditions in manatees. Monocytosis has been documented in manatees with cold-stress syndrome, although it is not known if the monocyte counts in that study included the bilobed variants (30). If the proportions of the latter cells increase with specific diseases, misclassification as lymphocytes may have more clinical relevance in manatees.…”

Lipidomics reveals specific lipid molecules associated with cold stress syndrome in the Florida manatee (Trichechus manatus latirostris)

“…However, lipidomic analyses can provide a more comprehensive assessment of the specific molecular lipid species that are altered during cold stress, beyond traditional spectrophotometric measurements that are used to determine total lipid class concentrations. Serum cholesterol and total triacylglycerol levels have been shown to be altered as a result of cold stress in manatees (Martony et al 2019). Yet prior to this study, specific blood lipid ratios between healthy and cold-stressed manatees have not been explored.…”

Wischnewsky spots in cases of fatal hypothermia in cattle

“…In other animal species, this finding is rarely described. However, it has already been documented in two dogs found dead in an extremely cold environment (Stern & Vieson 2017), in suspected cases of hypothermia in a free-living monkey and a domestic rabbit (Almeida et al 2021), and in manatees that presented cold stress (Martony et al 2019).…”