Effects of time and storage temperature on selected biochemical analytes in plasma of red-eared sliders (Trachemys scripta elegans)

Clinical Pathology of Box Turtles (Terrapene spp.)

Box turtles are commonly presented for veterinary care and clinicopathologic testing is a vital component of case management. This article summarizes recent literature about box turtle clinical pathology and identifies directions for future research.

COMPARING THE EFFECTS OF LITHIUM HEPARIN AND DIPOTASSIUM ETHYLENEDIAMINETETRAACETIC ACID ON HEMATOLOGIC VALUES IN EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA)

Anticoagulants are employed to prevent clotting and preserve cellular morphology for clinical pathology tests. Lithium heparin (LH) is the most frequently used anticoagulant in chelonians; however, dipotassium ethylenediaminetetraacetic acid (EDTA) may be superior in some species. Although eastern box turtles' (Terrapene carolina carolina) hematologic parameters are well studied, the effects of different anticoagulants on hematology in this species are unknown. This study evaluated the effects of LH and EDTA on hematologic values in free-living eastern box turtles (N = 59). Blood samples were collected from eastern box turtles in Illinois and immediately divided between LH and EDTA microtainers, and complete blood counts were performed on each sample. Grossly, plasma from EDTA blood samples was frequently and significantly hemolyzed. Blood mixed with LH had higher packed cell volume (PCV) (P = 0.04), white blood cell count (WBC) determined by Leukopet (P < 0.0001), WBC determined by blood film estimate (P < 0.0001), absolute heterophils (P = 0.007), absolute lymphocytes (P < 0.0001), and lower total solids (P < 0.0001) and absolute monocytes (P = 0.0001) than blood mixed with EDTA. All relative leukocyte counts were significantly different between the anticoagulants (P < 0.0001). EDTA apparently lysed turtle erythrocytes in this study, making it difficult to accurately count white blood cells and artificially lowering PCV. These findings demonstrate that EDTA should not be used in eastern box turtles.

Pre-/analytical factors affecting whole blood and plasma glucose concentrations in loggerhead sea turtles (Caretta caretta)

Blood glucose is vital for many physiological pathways and can be quantified by clinical chemistry analyzers and in-house point-of-care (POC) devices. Pre-analytical and analytical factors can influence blood glucose measurements. This project aimed to investigate pre-analytical factors on whole blood and plasma glucose measurements in loggerhead sea turtles (Caretta caretta) by evaluating the effects of storage (refrigeration) up to 48h after sampling and of packed cell volume (PCV) on whole blood glucose analysis by POC glucometer (time series n = 13); and by evaluating the effects of storage (room temperature and refrigeration) on plasma glucose concentrations using a dry slide chemistry analyzer (DCA) at various conditions: immediate processing and delayed plasma separation from erythrocytes at 24h and 48h (time series n = 14). The POC glucometer had overall strong agreement with the DCA (CCC = 0.76, r = 0.84, C_b = 0.90), but consistently overestimated glucose concentrations (mean difference: +0.4 mmol/L). The POC glucometer results decreased significantly over time, resulting in a substantial decline within the first 2h (0.41±0.47 mmol/L; 8±9%) that could potentially alter clinical decisions, thereby highlighting the need for immediate analysis using this method. The effects of PCV on glucose could not be assessed, as the statistical significance was associated with one outlier. Storage method significantly affected plasma glucose measurements using DCA, with room temperature samples resulting in rapid decreases of 3.57±0.89 mmol/L (77±9%) over the first 48h, while refrigerated samples provided consistent plasma glucose results over the same time period (decrease of 0.26±0.23 mmol/L; 6±5%). The results from this study provide new insights into optimal blood sample handling and processing for glucose analysis in sea turtles, show the suitability of the POC glucometer as a rapid diagnostic test, and confirm the reliability of plasma glucose measurements using refrigeration. These findings emphasize the need to consider pre-/analytical factors when interpreting blood glucose results from loggerhead sea turtles.

Hematology and plasma biochemistries in the Blanding's turtle (Emydoidea blandingii) in Lake County, Illinois

Chelonians are one of the most imperiled vertebrate taxa on the planet due to changes in the environment, anthropogenic influences, and disease. Over the last two decades, conservation strategies including nest protection, head-starting and meso-predator control have been successfully adopted by the Lake County Forest Preserve District for a population of state-endangered Blanding's turtles (Emydoidea blandingii) in Illinois. Only recently have efforts expanded to assess the effects of management action on turtle health. The objectives of this study were to 1) establish reference intervals for 16 hematologic and plasma biochemical analytes in free-ranging Blanding's turtles, 2) characterize demographic and temporal drivers of clinical pathology values including age class, sex, month, and year, and 3) describe bloodwork differences between a managed (SBCP) and unmanaged (IBSP) study site. Hematology and plasma biochemistries were performed for 393 turtles from 2017-18 at two sites in the Lake Plain region. Subject or population-based reference intervals were established based on the index of individuality per American Society for Veterinary Clinical Pathology guidelines. Analytes differed by age class [packed cell volume (PCV), total solids (TS), total white blood cell counts (WBC), heterophils, lymphocytes, heterophil:lymphocyte ratio (H:L), total calcium (Ca), calcium:phosphorous (Ca:P), bile acids (BA), aspartate aminotransferase (AST)], sex [H:L, Ca, phosphorus (P), Ca:P, creatine kinase (CK)], month [eosinophils, H:L, Ca, P, uric acid (UA), AST], and year [PCV, WBC, lymphocytes, basophils, H:L, Ca, P, UA]. Several analytes also varied by site [PCV, TS, monocytes, eosinophils, P, UA, AST], suggesting that health status may be affected by habitat management or lack thereof. The results of this study provide a baseline for ongoing health assessments in this region as well as across the Blanding's turtle range.