Serum biochemistry reference intervals of live wild dugongs (Dugong dugon) from urban coastal Australia

A Multi-Matrix Metabolomic Approach in Ringed Seals and Beluga Whales to Evaluate Contaminant and Climate-Related Stressors

As a high trophic-level species, ringed seals (Pusa hispida) and beluga whales (Delphinapterus leucas) are particularly vulnerable to elevated concentrations of biomagnifying contaminants, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and mercury (Hg). These species also face climate-change-related impacts which are leading to alterations in their diet and associated contaminant exposure. The metabolomic profile of marine mammal tissues and how it changes to environmental stressors is poorly understood. This study characterizes the profiles of 235 metabolites across plasma, liver, and inner and outer blubber in adult ringed seals and beluga whales and assesses how these profiles change as a consequence of contaminants and dietary changes. In both species, inner and outer blubber were characterized by a greater proportion of lipid classes, whereas the dominant metabolites in liver and plasma were amino acids, carbohydrates, biogenic amines and lysophosphatidylcholines. Several metabolite profiles in ringed seal plasma correlated with δ13C, while metabolite profiles in blubber were affected by hexabromobenzene in ringed seals and PBDEs and Hg in belugas. This study provides insight into inter-matrix similarities and differences across tissues and suggests that plasma and liver are more suitable for studying changes in diet, whereas liver and blubber are more suitable for studying the impacts of contaminants.

Development of a polyclonal anti-dugong immunoglobulin G (IgG) antibody with evaluation of total plasma IgG in a living dugong (Dugong dugon) population

Species-specific antibodies (Ab) for the measurement of immunoglobulins (Ig) are valuable tools for determining the humoral immune status of threatened and endangered wildlife species such as dugongs. However, no studies have reported antibody reagents against dugong immunoglobulin. The object of this study was to develop an Ab with specificity for dugong IgG and apply this tool to survey total IgG levels in plasma samples from a live wild population of dugongs in southern Queensland, Australia. Dugong IgG was isolated from plasma by protein A/G column chromatography and a polyclonal antiserum was successfully raised against the dugong IgG through immunization of mice. The anti-dugong antiserum was reactive with dugong serum but not immunoglobulin from other species such as rats and humans. When tested against a panel of dugong plasma samples, relative IgG levels from dugongs (n = 116) showed biologically relevant relationships with pregnancy status and a principal component of Body Mass Index (BMI)/globulin/fecal glucocorticosteroid (chronic stress) levels combined, which together accounted for 9.2% of the variation in total Ig levels. Together these data suggest that dugongs show variation in total IgG and that this correlates with some physiological parameters of dugong health.

Method comparison and generation of plasma biochemistry RIs for the White rhinoceros on a point-of-care and wet chemistry analyzer

BACKGROUND

Plasma biochemistry analysis may aid the management of White rhinoceros with poaching or other injuries. Analyzer- and species-specific RIs are necessary to evaluate health status and identify abnormalities.

OBJECTIVES

The purpose of the study was to perform a comparison study between the IDEXX VetTest and Roche Cobas Integra 400 Plus, and to generate analyzer-specific RIs for White rhinoceros according to published guidelines.

METHODS

Comparison was carried out using White rhinoceros plasma samples from healthy and diseased animals. Reference intervals for albumin, ALT, AST, CK, creatinine, GGT, globulins, glucose, phosphorus, total proteins, and urea were determined from a sample group of chemically immobilized healthy adult White rhinoceros from the Kruger National Park, South Africa.

RESULTS

There was a significant analytic bias for all analytes between the 2 analyzers. Results for glucose and total protein were clinically equivalent based on total allowable error limits. Reference intervals were generated from 51 individuals (26 male, 25 female) for all analytes except ALT on the VetTest.

DISCUSSION

The type, direction, and magnitude of bias between the VetTest and Cobas appeared to be species- and analyzer-specific, when compared to other studies. These measures of bias may be used for comparability testing. Reference intervals for total proteins (VetTest 77-108 g/L, Cobas 77-110 g/L) and globulins (VetTest 47-79 g/L, Cobas 51-87 g/L) were high compared to other uneven-toed ungulates.

CONCLUSION

Plasma samples from White rhinoceros can be evaluated on both the VetTest and Cobas. Results from this study will aid conservation efforts directed toward this species.

Hematology of dugongs (Dugong dugon) in southern Queensland

BACKGROUND

Little is known of the hematology of the dugong (Dugong dugon), a secretive and endangered coastal marine mammal.

OBJECTIVES

This paper reports hematologic reference intervals (RI) for dugongs and characterizes morphologic, cytochemical, and ultrastructural features of dugong leukocytes.

METHODS

Blood was collected from live, apparently healthy dugongs and analyzed using Cell-Dyn 3700 or Sysmex XT-2000iV hematology analyzers. Blood films were subjected to a series of cytochemical stains, and leukocyte structure was examined using transmission electron microscopy.

RESULTS

Reference intervals were established for 14 hematologic variables, total solids, and fibrinogen for 92 dugongs. Significant differences in some variables were found for animal size class, sex, and pregnancy status, and between analyzers. Subadults had higher leukocyte and lymphocyte counts than adults. Males had higher total solids and fibrinogen than females. Pregnant females had higher HCT, MCV, and circulating nucleated RBC, and lower platelet counts than nonpregnant females. Lymphocytes were usually the predominant circulating leukocyte. Heterophil cytoplasmic granules were abundant, fine, round to ovoid, and intensely eosinophilic, and round to ovoid or rod-shaped, and variably electron dense in electron microscopy. Eosinophils contained larger round eosinophilic to orange cytoplasmic granules, which ultrastructurally were bicompartmental with a round eccentric electron-dense core. Cytochemical staining of dugong heterophils suggests biochemical similarity to those of manatees and elephants, and for eosinophils, similarity to those of elephants, ruminants, and equids.

CONCLUSIONS

Generation of hematologic RI and characterization of leukocyte morphology improves evaluation of dugong health across this population and serves as a reference for other populations outside southern Queensland.