Blood gases, biochemistry, and hematology of Galapagos green turtles (Chelonia mydas)

Sedation and general anaesthesia of crocodilians: a systematic review

Sedation and general anaesthesia of crocodilians pose unique challenges due to their aggressive nature, poikilothermic physiology, and specific anatomical and physiological characteristics, all factors that complicate crocodilian anaesthesia. This review aimed to systematically review the literature regarding sedation and general anaesthesia of crocodilians with focus on efficacy and impact on vital parameters. A systematic literature search was performed according to PRISMA guidelines on May 2, 2023 in the databases Embase, PubMed, Scopus and Web of Science. Publications were excluded based on predefined exclusion criteria, which encompassed non-standard publications and publications unrelated to crocodilians, with fewer than five animals and/or with insufficient data on sedation and general anaesthesia. Five key factors were used to evaluate the strength of evidence: number of included animals, study design, definition of recovery time, blinded assessment of recovery and conflict of interest. Ten publications were included in this systematic review. Drugs used included alpha-2-adrenoceptor agonists, dissociative anaesthetics, benzodiazepines, neuromuscular blocking agents, propofol, alfaxalone, and inhalant gasses. The studies included in total 55 Alligator mississippiensis, 110 Crocodylus porosus, 15 Crocodylus johnstoni, and 15 Crocodylus niloticus. Factors such as temperature, administration route, dose, species, and age influenced protocols for sedation and general anaesthesia of crocodilians. The studies included used five different study designs. Only one study included a control group, done on retrospectively collected data. Blinded recovery assessments and declarations of no conflict of interest were noted in some studies. The use of four distinct recovery definitions posed challenges to comparability in this systematic review. The studies reported that medetomidine provided stable and reversible sedation, although it depressed heart rate. Alfaxalone was less stable outside the optimal temperature range. Intubation and inhalation anaesthesia were effective, and adrenaline reduced the length of the recovery period. Overall, the review provides valuable insights for veterinarians, researchers, and wildlife professionals involved in sedation and general anaesthesia of the crocodilian species, however, the literature is limited, and further research is needed to improve evidence-based medical management.

Research on antibiotic resistance genes in wild and artificially bred green turtles (Chelonia mydas)

Sea turtles, vital to marine ecosystems, face population decline. Artificial breeding is a recovery strategy, yet it risks introducing antibiotic resistance genes (ARGs) to wild populations and ecosystems. This study employed metagenomic techniques to compare the distribution characteristics of ARGs in the guts of wild and artificially bred green turtles (Chelonia mydas). The findings revealed that the total abundance of ARGs in C. mydas that have been artificially bred was significantly higher than that in wild individuals. Additionally, the abundance of mobile genetic elements (MGEs) co-occurring with ARGs in artificially bred C. mydas was significantly higher than in wild C. mydas. In the analysis of bacteria carrying ARGs, wild C. mydas exhibited greater bacterial diversity. Furthermore, in artificially bred C. mydas, we discovered 23 potential human pathogenic bacteria (HPB) that contain antibiotic resistance genes. In contrast, in wild C. mydas, only one type of HPB carrying an antibiotic resistance gene was found. The findings of this study not only enhance our understanding of the distribution and dissemination of ARGs within the gut microbial communities of C. mydas, but also provide vital information for assessing the potential impact of releasing artificially bred C. mydas on the spread of antibiotic resistance.

Blood Fluke Infection (Spirorchidiasis) and Systemic Granulomatous Inflammation: A Case Study of Green Sea Turtles (Chelonia mydas) on Jeju Island, South Korea

Despite the precarious state of marine turtles as a highly endangered species, our understanding of their diseases remains limited. This case report presents a detailed pathological investigation of spirorchiidiasis, a blood fluke infection that poses a substantial threat to marine turtles. This retrospective study examined three cases of spirorchiid-infected sea turtles, specifically, green sea turtles stranded on Jeju Island, South Korea. Premortem examination of the three spirorchiid-infected green sea turtles demonstrated nonspecific clinical symptoms; blood analysis revealed dehydration, malnutrition, and anemia. Computed tomography scans provided insights into severe pulmonary and extrapulmonary manifestations, including the mass present in the joint region. Post-mortem examinations consistently indicated severe lung lesions and systemic manifestations, with histopathological examination confirming the presence of spirorchiid ova across various organs. Despite the global prevalence of spirorchiidiasis in sea turtles, disease severity varies regionally. This report provides a detailed demonstration of the pathology of spirorchiidiasis in sea turtles from Northeast Asia.

Comparison of the intestinal flora of wild and artificial breeding green turtles (Chelonia mydas)

Gut microbes are pivotal reference indicators for assessing the health status of animals. Before introducing artificially bred species into the wild, examining their gut microbe composition is crucial to help mitigate potential threats posed to wild populations. However, gut microbiological trait similarities between wild and artificially bred green turtles remain unexplored. Therefore, this study compared the gut microbiological characteristics of wild and artificially bred green turtles (Chelonia mydas) through high-throughput Illumina sequencing technology. The α-diversity of intestinal bacteria in wild green turtles, as determined by Shannon and Chao indices, significantly surpasses that of artificial breeding green turtles (p < 0.01). However, no significant differences were detected in the fungal α-diversity between wild and artificially bred green turtles. Meanwhile, the β-diversity analysis revealed significant differences between wild and artificially bred green turtles in bacterial and fungal compositions. The community of gut bacteria in artificially bred green turtles had a significantly higher abundance of Fusobacteriota including those belonging to the Paracoccus, Cetobacterium, and Fusobacterium genera than that of the wild green turtle. In contrast, the abundance of bacteria belonging to the phylum Actinobacteriota and genus Nautella significantly decreased. Regarding the fungal community, artificially bred green turtles had a significantly higher abundance of Fusarium, Sterigmatomyces, and Acremonium and a lower abundance of Candida and Rhodotorula than the wild green turtle. The PICRUSt2 analyses demonstrated significant differences in the functions of the gut bacterial flora between groups, particularly in carbohydrate and energy metabolism. Fungal functional guild analysis further revealed that the functions of the intestinal fungal flora of wild and artificially bred green turtles differed significantly in terms of animal pathogens-endophytes-lichen parasites-plant pathogens-soil saprotrophs-wood saprotrophs. BugBase analysis revealed significant potential pathogenicity and stress tolerance variations between wild and artificially bred green turtles. Collectively, this study elucidates the distinctive characteristics of gut microbiota in wild and artificially bred green turtles while evaluating their health status. These findings offer valuable scientific insights for releasing artificially bred green turtles and other artificially bred wildlife into natural habitats.

Hematological and genotoxic biomarkers in a natural population of freshwater turtles Trachemys dorbigni (Duméril & Bibron, 1835) (Testudines: Emydidae) living in an urban area in Southern Brazil

The present study aimed to report the morphometric and hematological indices and genotoxicity of a free-life population of D'Orbigny's slider turtles (Trachemys dorbigni) living in an urban area in Southern Brazil. For that, 16 specimens were randomly captured in an urban canal that receives irregular releases of wastewater. Biometrics and external visual changes were analyzed, such as turtle shell deformities, and the presence of parasites. Blood samples were collected to evaluate the hematological profile and the presence of micronuclei and other erythrocyte nuclear abnormalities as potential mutagenic and genotoxic effects. Water physicochemical parameters were also measured. Organisms with ectoparasites (31.25%) and small carapace deformations (56.25%) were observed, but maximum carapace length and weight were considered normal for the species according to the literature. The blood profile indicated low hemoglobin and hematocrit and a high number of total leukocytes, particularly eosinophils which characterize parasitic infections. A frequency of 0.12% for the micronucleus was considered basal, but the frequency of other erythrocyte abnormalities was evident, mainly of blebbed nuclei (63.79%), indicating chromosomal damage in the early stage. The results of this study suggest that natural populations of chelonian inhabiting urbanized areas are impacted by anthropogenic activities in the surrounding environment. Furthermore, it provides comprehensive data which can serve as a comparative model for environmental monitoring studies involving turtles.

Venous blood gases and electrolyte values of captive red foot tortoise (Chelonoidis carbonarius)

Blood gas analysis reflects the exchange of oxygen and carbon dioxide in the lungs. This test provides important information, since the relationship between these gases has a direct impact on the acid-basic balance in the body. Given the significance of blood gas analysis in Brazilian reptiles, this study set out to establish temperature-corrected and uncorrected reference intervals for venous blood gas measurements in Chelonoidis carbonarius, and to compare values between females and males. In this study, 19 animals were used, 8 males and 11 females. Blood samples were collected from the dorsal coccygeal vein, and the analyses were performed immediately after blood sample collection. The following parameters were measured: pH, PO2, HCO3-, TCO2, BEecf, Na, K, ICa, and Glu, and were compared between females and males. Additionally, pH, pCO2, and pO2 values were compared with and without temperature correction. Oxygen saturation and Na levels were significantly higher (p<0.05) in males. Furthermore, it was possible to infer that the lower the body temperature relative to the environmental temperature, the larger the difference in pH following temperature correction.

Health status and genetic compositions of green turtles (Chelonia mydas) foraging in Brunei Bay

Long-term monitoring of sea turtle aggregations is critical for understanding the impacts of environmental changes on their population health and habitat suitability. Brunei Bay is a significant foraging ground for green turtles in the South China Sea. We analyzed the body size, hematology and body condition of green turtles for their health status in their foraging ground in Brunei Bay over a period of nine years (2011-2019). Additionally, we used mitochondrial DNA (mtDNA) to evaluate changes in the size and genetic composition of green turtle aggregations. Our findings revealed that the size composition of the green turtle population varied seasonally, but there were no significant temporal changes in genetic and size compositions. Hematology parameters and Fulton's body condition index were consistent with those reported for apparently healthy green turtles. Furthermore, we found that blood reference intervals indicated the turtles were healthy. These results provide valuable baseline data for future comparisons with other foraging aggregations and for long-term monitoring of green turtles in Brunei Bay.

Blood analyte reference intervals and correlations with trace elements of immature and adult Eastern Pacific green turtles (Chelonia mydas) in coastal lagoons of Baja California Sur, México

Sea turtles can bioaccumulate high concentrations of potentially toxic contaminants. To better understand trace element effects on sea turtles' health, we established reference intervals for hematological and plasma biochemical analytes in 40 in-water, foraging immature and adult Eastern Pacific green turtles (Chelonia mydas) from two coastal lagoons in Baja California Sur, quantified whole blood concentrations of eight trace elements, and assessed their correlations. Rank-order trace element concentrations in both immature and adult turtles was zinc > selenium > nickel > arsenic > copper > cadmium > lead > manganese. Immature turtles had significantly higher copper and lower nickel and zinc concentrations. Additionally, a number of relationships between trace elements and blood analytes were identified. These data provide baseline information useful for future investigations into this population, or in other geographic regions and various life-stage classes.

Immune and stress physiology of two captively-housed tortoise species

Ecoimmunology affords us the ability to better understand immunological processes through consideration of external factors, such as the thermal microenvironment. This consideration is imperative when examining the immunological processes of ectothermic organisms like reptiles. Reptiles uniquely rely heavily on their innate immune function but remain poorly understood in immunological studies. In this study, we examined innate immunity in two zoo-housed tortoise species, the Indian star tortoise (Geochelone elegans, Schoepff, 1795) and northern spider tortoise (Pyxis arachnoides brygooi, Vuillemin & Domergue, 1972). Bacterial killing assays (BKAs) were optimized and used to assess the monthly immunocompetence of these tortoises to three different bacteria: Escherichia coli, Salmonella enterica, and Staphylococcus aureus. We evaluated differences in blood biochemistry values (lactate and glucose) among months and species as well as fecal corticosterone (CORT) between species. Lastly, we examined the potential influences of individual thermal microenvironments on bactericidal ability. Both G. elegans and P. a. brygooi demonstrated immunocompetence against all bacterial challenges, but only bactericidal ability against E. coli varied over months. Optimal BKA serum dilutions, blood glucose levels, and fecal CORT concentrations differed between the two species. Finally, there was evidence that the thermal microenvironment influenced the tortoises' bactericidal ability against E. coli. Through use of nonmodel organisms, such as tortoises, we are given insight into the inner workings of innate immunity and a better understanding of the complexities of the vertebrate immune system.

Diagnostic Use of Lactate in Exotic Animals

Monitoring blood lactate concentrations with a handheld, point-of-care (POC) meter is an efficient and inexpensive method of monitoring critically ill or anesthetized exotic patients. Serial monitoring of lactate allows early recognition of hypoperfusion, allowing for prompt implementation of resuscitative efforts. Reference ranges for exotic animals are currently sparse and often gathered from field studies of wild animals. In the absence of reference ranges, extrapolations can be made regarding mammals and birds, but may be more difficult in reptiles and amphibians.

Haematological and biochemical reference intervals for wild green turtles (Chelonia mydas): a Bayesian approach for small sample sizes

Animal health is directly linked to population viability, which may be impacted by anthropogenic disturbances and diseases. Reference intervals (RIs) for haematology and blood biochemistry are essential tools for the assessment of animal health. However, establishing and interpreting robust RIs for threatened species is often challenged by small sample sizes. Bayesian predictive modelling is well suited to sample size limitations, accounting for individual variation and interactions between influencing variables. We aimed to derive baseline RIs for green turtles (Chelonia mydas) across two foraging aggregations in North Queensland, Australia, using Bayesian generalized linear mixed-effects models (n = 97). The predicted RIs were contained within previously published values and had narrower credible intervals. Most analytes did not vary significantly with foraging ground (76%, 22/29), body mass (86%, 25/29) or curved carapace length (83%, 24/29). Length and body mass effects were found for eosinophils, heterophil:lymphocyte ratio, alkaline phosphatase, aspartate transaminase and urea. Significant differences between foraging grounds were found for albumin, cholesterol, potassium, total protein, triglycerides, uric acid and calcium:phosphorus ratio. We provide derived RIs for foraging green turtles, which will be helpful in future population health assessments and conservation efforts. Future RI studies on threatened species would benefit from adapting established veterinary and biomedical standards.

Relationship, difference, and diagnostic discordance between blood ionized and total calcium concentrations in client-owned chelonians

OBJECTIVE

To determine (1) the relationship, (2) the difference, and (3) the diagnostic discordance between blood total calcium concentration (tCa) and ionized calcium concentration (iCa) in a population of client-owned chelonian patients.

ANIMALS

161 consecutively admitted client-owned chelonians.

PROCEDURES

Results for tCa, iCa, and other variables were extracted from records. Bound calcium concentration (tCa - iCa) was calculated. General linear models were developed to evaluate factors affecting tCa, iCa and bound calcium concentrations. Diagnostic discordance between tCa and iCa was assessed.

RESULTS

iCa decreased with increasing albumin concentration, it was not influenced by sex, and it was lower in chelonians with disorders of the reproductive tract than in those with disorders of the endocrine/hemopoietic and urinary systems. Total calcium and bound calcium concentrations increased with increasing albumin concentration; they were higher in females and in chelonians with disorders of the reproductive tract. Of the 161 chelonians, 93 (57.7%; 95% CI, 49.7% to 65.5%) would have had a different diagnosis of calcium status based on tCa and iCa results (ie, diagnostic discordance). A 2.2 mmol/L cutoff value for bound calcium could differentiate chelonians with and without disorders of the reproductive tract with a sensitivity (95% CI) of 81.8% (64.5% to 93.0%) and specificity of 76.4% (68.0% to 83.5%).

CLINICAL RELEVANCE

tCa and iCa were related and were associated with albumin concentrations in chelonians. Evaluation of tCa or iCa alone is likely to result in underdiagnosis of alterations of the calcium status. Calculation of bound calcium concentration could help identify chelonians with reproductive disorders.

LACTIC ACIDOSIS INDUCED BY MANUAL RESTRAINT FOR HEALTH EVALUATION AND COMPARISON OF TWO POINT-OF-CARE ANALYZERS IN HEALTHY LOGGERHEAD SEA TURTLES (CARETTA CARETTA)

Sea turtles are often restrained manually for brief periods during veterinary evaluation and care in rescue, rehabilitation, research, and aquarium settings. Blood gas values and lactate are routinely evaluated during triage of sea turtles, and lactate clearance is of prognostic significance in cold-stunned individuals. Although increases in blood lactate have been associated with muscle exertion, experimental forced submergence, trawl and pound net capture, and general anesthesia, changes in blood lactate associated with short periods of manual restraint have not been evaluated. Venous blood gas and lactate values were tested in 16 juvenile loggerhead sea turtles (Caretta caretta) before and after manual restraint for a 15-min routine veterinary examination. The agreement of blood lactate values between two point-of care analyzers (i-STAT and Lactate Plus) was also compared. Blood pH and bicarbonate (HCO₃^-) decreased significantly (P < 0.001), and partial pressure of carbon dioxide (pCO₂) increased significantly (P < 0.0001) after 15 min. Lactate increased significantly between time points for both analyzers (P < 0.0001). Linear regression analysis showed excellent correlation for lactate measurements obtained on both analyzers (r = 0.998). The mean difference in lactate concentrations between the analyzers was statistically significant, indicating that the methods cannot be used interchangeably (P < 0.0001). Deming regression and Bland-Altman plots identified a slight negative proportional bias for lactate measurement by the Lactate Plus compared with the i-STAT. These results suggest that clinicians should evaluate blood gas values and lactate at the beginning of health evaluations and interpret serial lactate values in sea turtles with caution, because even short periods of manual restraint can induce lactic acidosis and considerably influence these values.

Disseminated Candidiasis and Candidemia Caused by Candida palmioleophila in a Green Sea Turtle (Chelonia mydas)

Simple Summary

A sub-adult green sea turtle was rescued and treated for shell fractures on the carapace and plastron. During the first 2 months, the turtle was kept dry-docked with a placement of an intravenous catheter. Pain management, antibiotic and anthelmintic therapy, fluid therapy, human albumin, force feeding, and wound debridement were provided to manage the shell fractures and to control the infection. After 2 months of care, small budding yeasts were noted on the turtle’s blood smears. Blood cultures yielded yeast-like colonies that were later identified as Candida palmioleophila. The patient was then treated with an antifungal agent and the catheter was removed. Approximately 3.5 months later, the carapace and plastron wounds had healed. However, the turtle died at 7.5 months after rescue. The postmortem examination revealed disseminated yeast in joints, bones, brain, and lungs. This study aims to improve the veterinary medical care and, therefore, enhance the conservation of endangered sea turtles by describing a rare report of systemic C. palmioleophila infection.

Abstract

A sub-adult green sea turtle (Chelonia mydas) was rescued and treated for carapace and plastron shell fractures. The turtle was kept dry-docked for the first 2 months with a placement of a long-term jugular central venous catheter (CVC). Pain management, aggressive antibiotic and anthelmintic therapy, fluid therapy, force feeding, and wound debridement were provided to manage the shell fractures and control bacteremia. Human albumin was administered to treat severe hypoalbuminemia. On day 59, small budding yeasts were noted on the blood smears. Candidemia was confirmed by blood culture, as the yeasts were identified as Candida palmioleophila by the molecular multi-locus identification method. The CVC was removed, and the patient was treated with itraconazole. Although the carapace and plastron wounds had epithelized by 5.5 months after the rescue, the turtle died unexpectedly by 7.5 months. The postmortem examination revealed numerous necrogranulomas with intralesional yeasts, morphologically compatible with Candida spp., in joints, bones, brain, and lungs, suggestive of disseminated candidiasis. We describe a rare case of candidemia in the veterinary field. To our knowledge, this is the first report of candidiasis caused by C. palmioleophila in a reptile. The present results should improve veterinary medical care and, therefore, enhance the conservation of endangered sea turtle species.

Agreement between hematocrits measured with electrical conductivity on the i-STAT analyzer and manual packed cell volume measurements in 148 chelonian patients

BACKGROUND

Point-of-care (POC) analyzers are increasingly used for diagnostic testing in exotic animals. A few studies with small sample sizes, evaluating agreement between hematocrit (Hct) and packed cell volume (PCV) measurements in chelonians, showed conflicting results.

OBJECTIVE

We aimed to assess the agreement between Hct values measured with a POC analyzer and manual PCV measurements in venous samples from 148 chelonians.

METHODS

All chelonians that underwent bloodwork for clinical reasons had Hct measured with an analyzer employing electrical conductivity (i-STAT, Abbott), PCVs measured using centrifugation, and total solids (TS) measured with refractometry. Bland-Altman plots were built to assess agreement between the measurements. Generalized linear mixed models were used to determine the effect of different variables on the difference between Hct and PCV.

RESULTS

Of 192 chelonians sampled during this period, 148 had Hct, PCV, and TS results. Hct significantly underestimated PCV, with a mean difference between the techniques of -3.8% (95% CI: -4.5 to -3.2; LoA: -11.5 to 3.8). There was a negative correlation between the value of TS and the difference between the methods. Controlling for other factors, the magnitude of the disagreement was not affected by the sex of the chelonian but was smaller in red-eared sliders (Trachemys scripta elegans).

CONCLUSIONS

Hct values measured with electrical conductivity in chelonians significantly underestimated manual PCVs by about 4%. This difference should be considered whenever an Hct measured on a POC analyzer using electrical conductance is used in chelonian patient assessments.

Health and nutrition of loggerhead sea turtles (Caretta caretta) in the southeastern United States

Loggerhead sea turtles (Caretta caretta) are opportunistic carnivores that feed primarily on benthic invertebrates and fish. Sea turtle rehabilitation requires provision of a species-specific, balanced diet that supplies nutrition similar to that of a wild diet; this can be challenging because free-ranging loggerheads' diets vary depending on their life stage and geographic location, with predominant prey species dictated by local availability. The goal of this study was to better understand the nutritional needs of subadult and adult loggerheads in rehabilitation. This was accomplished by conducting a retrospective survey of stomach contents identified during gross necropsy of 153 deceased loggerheads that stranded in coastal Georgia, USA. A total of 288 different forage items were identified; the most frequently observed prey items belong to the subphylum Crustacea (N = 131), followed by bony fish (Osteichthyes; N = 45), gastropod mollusks (N = 40), bivalve mollusks (N = 23), and Atlantic horseshoe crabs (Limulus polyphemus; N = 15). The proportions of certain prey items differed significantly with turtle size; adult turtles ate proportionately more gastropods (p = 0.001), and subadults ate proportionately more fish (p = 0.01). Stomach contents information was used to determine common local prey items (blue crab, cannonball jellyfish, horseshoe crab, whelk), which were evaluated for nutritional content. Additionally, we compared hematology and plasma biochemistry profiles (including proteins, trace minerals, and vitamins) between four cohorts of loggerhead turtles, including free-ranging subadults and adults, nesting females, and loggerheads undergoing rehabilitation. This information was applied to inform a regionally specific, formulated diet for tube feeding, and a supplement containing vitamins and minerals for captive loggerheads, to more closely approximate the nutritional content of their natural diet. Assessing the regional and temporal variability in loggerhead diets is an important component in their effective conservation because resultant data can be used to help understand the impacts of environmental perturbations on benthic food webs.

Characterization of oral and cloacal microbial communities in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) during the time course of rehabilitation

Microbial communities of animals play a role in health and disease, including immunocompromised conditions. In the northeastern United States, cold-stunning events often cause endangered Kemp's ridley turtles (Lepidochelys kempii) to become stranded on beaches in autumn. These sea turtles are admitted to rehabilitation facilities when rescued alive and are presumed immunocompromised secondary to hypothermia. To better understand the role that microbes play in the health of cold-stunned sea turtles, we characterized the oral and cloacal microbiome from Kemp's ridley turtles at multiple timepoints during rehabilitation, from admission to pre-release, by using Illumina sequencing to analyze the 16S rRNA gene. Microbial communities were distinct between body sites and among turtles that survived and those that died. We found that clinical parameters such as presence of pneumonia or values for various blood analytes did not correlate with oral or cloacal microbial community composition. We also investigated the effect of antibiotics on the microbiome during rehabilitation and prior to release and found that the type of antibiotic altered the microbial community composition, yet overall taxonomic diversity remained the same. The microbiome of cold-stunned Kemp's ridley turtles gradually changed through the course of rehabilitation with environment, antibiotics, and disease status all playing a role in those changes and ultimately the release status of the turtles.

MEASURING FAT CONTENT USING COMPUTED TOMOGRAPHY TO ESTABLISH A BODY CONDITION INDEX IN FREE-RANGING BLANDING'S TURTLES (EMYDOIDEA BLANDINGII) IN ILLINOIS

Health assessment of free-ranging populations requires an integrated approach, often incorporating a method to measure mass as a representation of the animals' ability to utilize environmental resources. In chelonians, direct measurements of mass have historically served as a corollary for body condition. However, this method may not accurately represent the true fat volume (FV) and may be skewed by the presence of eggs, shell size, or muscle mass. The objective of this study was to use computed tomography (CT) to develop a model for determining body condition index (BCI) in free-ranging Blanding's turtles (Emydoidea blandingii). Mass, shell measurements, and FV were measured by CT in 65 free-ranging Blanding's turtles from Lake and DuPage counties in Illinois. Twenty-one different models were built for BCI using both FV and fat percentage (FP) as dependent variables. The best fit model for FP included the relationship between mass and carapace length with nearly 60% model support. The model for FV demonstrated a similar relationship but had only 18% support. Linear models with BCI as the dependent variable showed that juveniles had a higher FP than adults and females with more eggs had a lower FP. FP can be calculated in the field with nearly 60% accuracy compared to CT-assessed FP as a component of a physical exam and population health survey to assess the effectiveness of conservation efforts for the endangered Blanding's turtle.

Disease risk analysis in sea turtles: A baseline study to inform conservation efforts

The impact of a range of different threats has resulted in the listing of six out of seven sea turtle species on the IUCN Red List of endangered species. Disease risk analysis (DRA) tools are designed to provide objective, repeatable and documented assessment of the disease risks for a population and measures to reduce these risks through management options. To the best of our knowledge, DRAs have not previously been published for sea turtles, although disease is reported to contribute to sea turtle population decline. Here, a comprehensive list of health hazards is provided for all seven species of sea turtles. The possible risk these hazards pose to the health of sea turtles were assessed and "One Health" aspects of interacting with sea turtles were also investigated. The risk assessment was undertaken in collaboration with more than 30 experts in the field including veterinarians, microbiologists, social scientists, epidemiologists and stakeholders, in the form of two international workshops and one local workshop. The general finding of the DRA was the distinct lack of knowledge regarding a link between the presence of pathogens and diseases manifestation in sea turtles. A higher rate of disease in immunocompromised individuals was repeatedly reported and a possible link between immunosuppression and environmental contaminants as a result of anthropogenic influences was suggested. Society based conservation initiatives and as a result the cultural and social aspect of interacting with sea turtles appeared to need more attention and research. A risk management workshop was carried out to acquire the insights of local policy makers about management options for the risks relevant to Queensland and the options were evaluated considering their feasibility and effectiveness. The sea turtle DRA presented here, is a structured guide for future risk assessments to be used in specific scenarios such as translocation and head-starting programs.

Blood oxygen stores of olive ridley sea turtles, Lepidochelys olivacea are highly variable among individuals during arribada nesting

Sea turtles dive with a full lung of air and these O₂ stores are supplemented by O₂ stored in blood and muscle. Olive ridley sea turtles exhibit polymorphic nesting behavior, mass nesting behavior called arribada, where thousands of turtles will nest at once, and solitary nesting behavior. The potential physiological differences between the individuals using these strategies are not well understood. We measured blood volume and associated variables, including blood hemoglobin content and hematocrit, to estimate total blood O₂ stores. There were no significant differences in mean values between nesting strategies, but arribada nesting individuals were more variable than those performing solitary nesting. Mass-specific plasma volume was relatively invariant among individuals but mass specific blood volume and blood oxygen stores varied widely, twofold and threefold, respectively. Blood O₂ stores represented 32% of total body O₂ stores. Under typical mean diving conditions of 26 °C and high levels of activity, blood stores confer ~ 14 min to aerobic dive times and are likely critical for the long duration, deep diving exhibited by the species. Individual differences in blood O₂ stores strongly impact estimated aerobic dive limits and may constrain the ability of individuals to respond to changes on ocean climate.

Comparison of Dilution on Eastern Box Turtle (Terrapene carolina carolina) and Marine Toad (Rhinella marinus) Blood Parameters as Measured on a Portable Chemistry Analyzer

Biochemical testing is an important clinical tool in evaluating the physiology of reptiles and amphibians. Suitable point of care analyzers can allow for rapid delivery of results, but small patient size can inhibit sufficient sample collection. This study evaluated the utility of sample dilution with sterile distilled water as a means of biochemical evaluation when sample volume is limited. Blood was collected from 12 eastern box turtles (Terrapene carolina carolina) and 12 marine toads (Rhinella marinus) and analyzed via i-STAT CHEM8+ cartridges. Two undiluted samples and two samples diluted 1 : 1 with sterile water were evaluated immediately following collection for each animal in the study. Analytes reported in the diluted samples were limited to glucose, ionized calcium, and total carbon dioxide. The expected dilution ratio value of diluted to undiluted samples was 0.5, of which glucose in both turtles and toads was nearest. Dilution ratio values for ionized calcium, however, were higher than expected in both turtles and toads. Sample dilution is not recommended for most analytes included on the CHEM8+ cartridge due to values occurring outside the limits of detection for the analyzer. Glucose and ionized calcium values obtained on diluted samples should be interpreted with caution but may provide clinical utility in reptile and amphibian patients where sample volume is limited.

Venous blood gas and biochemical analysis of wild captured green turtles (Chelonia mydas) and Kemp's ridley turtles (Lepidochelys kempii) from the Gulf of Mexico

Blood was collected from wild captured green and Kemp’s ridley turtles off the west coast of Florida, USA. Blood gases and biochemical values were analyzed using a point of care (POC) device in the field. Analytes include pH, partial pressure of carbon dioxide (pCO₂), partial pressure of oxygen (pO₂), total carbon dioxide (TCO₂), bicarbonate (HCO₃), base excess (BE), oxygen saturation (sO₂), lactate, sodium (Na), potassium (K), chloride (Cl), total carbon dioxide (TCO₂), anion gap, ionized calcium, glucose, blood urea nitrogen (BUN), creatinine (Crea), hematocrit (Hct), and hemoglobin (Hb). These are novel data for wild healthy Kemp’s ridley turtles, and results for green turtles were generally consistent with past studies of green turtles with exceptions primarily in blood gas values. Ninety percent of the green turtles had fibropapillomatosis (FP), but none of the blood analytes were correlated with disease severity. Only BUN was correlated with weight of green turtles, and there was no correlation between blood parameters and weight of Kemp’s ridley turtles. This study provides data that are useful in understanding the physiologic status of sea turtles specific to this region, allowing for comparisons to other populations, life stages, and disease states.

Anaesthesia of hatchling green sea turtles (Chelonia mydas) with intramuscular ketamine-medetomidine-tramadol

OBJECTIVE

To characterise intramuscular ketamine-medetomidine-tramadol anaesthesia in hatchling green sea turtles (Chelonia mydas).

STUDY DESIGN

Prospective clinical trial.

ANIMALS

Ten hatchling green sea turtles.

MATERIALS AND METHODS

Prior to anaesthesia, cardiopulmonary parameters, cloacal temperature, and venous blood gas and biochemistry were obtained from hatchling green sea turtles while they were being gently restrained. Animals were then anaesthetised with ketamine (5 mg kg^-1 ), medetomidine (0.05 mg kg^-1 ) and tramadol (5 mg kg^-1 ) via intramuscular injection. Turtles were checked for the depth of anaesthesia at five-min intervals by recording reflexes (righting, palpebral, pinch, cloacal) and measuring heart rate, respiratory rate and cloacal temperature. After 20 min, a second venous blood sample was obtained for further blood gas and biochemical analysis and the medetomidine was antagonised using atipamezole (5:1 medetomidine, 0.25 mg kg^-1 ).

RESULTS

All turtles were successfully anaesthetised with a mean time to induction of 3.4 min (±1). In all animals, a loss of reflexes (except for palpebral reflex) and voluntary movement was observed for the entire 20 min. Anaesthesia resulted in marked apnoea for the duration of the procedure. Venous blood gas and biochemistry analysis indicated that a 20 min period of apnoea had no measurable effects on venous blood gas results. All turtles recovered uneventfully after atipamazole antagonisation, with a mean time to first breath 4.5 min (±3.7), and mean recovery time 15.5 min (±15.4).

CONCLUSIONS AND CLINICAL RELEVANCE

Intramuscular ketamine-medetomidine-tramadol, antagonised with atipamazole appears to be an effective anaesthetic protocol in hatchling green sea turtles for short procedures with no deleterious effects on venous blood gases or biochemistry.

Light Microscopic and Ultrastructural Characteristics of Heterophil Toxicity and Left-shifting in Green Sea Turtles (Chelonia mydas) from Taiwan

Heterophil toxic change (TC) and left-shifting (LS) are widely used as indicators of accelerated granulopoiesis. However, the ultrastructure of heterophil TC and LS in sea turtles remain poorly understood. This study aimed to describe the ultrastructural characteristics of sea turtle TC and LS heterophils, compare the staining quality of accessible staining methods, and provide a better understanding of the clinical applications and limitations of heterophil TC and LS examinations. Blood samples were collected from 21 rescued sea turtles from January 2017 to September 2018. Morphologic (n = 22) and ultrastructural (n = 15) examination of TC and LS heterophils were performed, and the qualities of three staining methods (Wright-Giemsa stain, Diff-Quik stain and Liu's stain) were analyzed to diagnose TC and LS heterophils. In addition, the diagnostic values of TC and LS heterophils were examined. Diff-Quik stain was significantly inferior in the assessment of heterophil TC and/or LS comparing to the Wright-Giemsa stain and Liu's stain (Mann-Whitney test, P < 0.001). Microscopic examinations of heterophil TC and/or LS were comparable to transmission electron microscopy examinations (Cohen's kappa coefficient, κ = 1). The correlation between the presence of heterophil TC and/or LS and clinical inflammatory state was weak (Spearman's rank correlation coefficient, rs = 0.171, p = 0.445). In conclusion, this is the first study to describe the ultrastructural characteristics of reptile TC and LS heterophils. Wright-Giemsa stain and Liu's stain were suitable staining methods for the microscopic observations of TC and LS heterophil in sea turtles. Given the poor correlation between TC and/or LS and clinical findings, TC and LS are not a suitable diagnostic indicator of green sea turtles' inflammation status.

Diagnosis and Surgical Management of a Paratesticular Cyst in a Rehabilitating Juvenile Male Green Turtle (Chelonia mydas)

A juvenile green turtle (Chelonia mydas) undergoing rehabilitation for cold stunning exhibited an asymmetric bulging of the left caudal plastron and was diagnosed with a large intra-coelomic mass based on radiographical findings. Ultrasonography further identified a fluid-filled structure within the caudal coelom. Cytological evaluation of fluid obtained from the structure was consistent with a transudate, and thus, a cyst of unknown origin was suspected. Computed tomography imaging was pursued to further characterize the extent and location of the mass, which occupied ~50% of the total coelomic cavity volume. Conservative management with monitoring and occasional drainage of the mass did not result in improvements; thus, an exploratory laparoscopy for further investigation and surgical planning was elected. Intra-coelomic surgery was performed to remove a thick-walled cystic mass associated with the left gonad. Histopathology confirmed a paratesticular cyst continuous with, and possibly originating from, the epididymis. Post-surgical recurrence of the cyst was not appreciated, and the animal was successfully released 1 year after admission. Unrelated to the cyst, the turtle developed acute severe anemia on two occasions throughout rehabilitation that responded to modification of antimicrobial treatment and subsequent steroid administration. To the authors' knowledge, this is the first report of a paratesticular cyst in a reptile.

Venous hematology, biochemistry, and blood gas analysis of free-ranging Eastern Copperheads (Agkistrodon contortrix) and Eastern Ratsnakes (Pantherophis alleghaniensis)

Hematology, plasma biochemistry, and blood gas analysis were performed on venous samples obtained from free-ranging Eastern Copperheads (Agkistrodon contortrix) and Eastern Ratsnakes (Pantherophis alleghaniensis) in central North Carolina during a mark-recapture study conducted from April to October 2015 at the North Carolina Zoo. Blood samples were collected from 31 (15 male and 16 female) free-ranging copperheads and 34 (20 male and 14 female) free-ranging ratsnakes at the beginning and end of restraint. Restraint was performed for morphometric measurements, sex determination, and identification via placement of intracelomic passive integrated transponder (PIT) tags and marking of ventral scutes with a handheld electrocautery unit. Blood gas analytes were measured at the beginning of restraint and compared to analytes measured at the end to evaluate for changes secondary to handling. Total restraint time prior to the first blood sampling was 1.4 ± 0.4 mins (mean ± SD) and 1.0 ± 0.2 mins (mean ± SD) and restraint time prior to second blood sampling was 12.5 ± 2.4 mins (mean ± SD) and 13.5 ± 3.4 mins (mean ± SD) for copperheads and ratsnakes, respectively. Blood lactate concentrations at the beginning of restraint were similar for both species. Lactate concentrations increased significantly and pH decreased significantly for both species at the end of restraint when compared to the beginning of restraint. Furthermore, lactate concentrations at the end of restraint were significantly elevated in ratsnakes compared to copperheads. This study provides guidelines for interpretation of venous hematology, plasma biochemistry, and blood gas values for free-ranging copperheads and ratsnakes in central North Carolina and demonstrates the physiological response to venous blood gas analytes secondary to capture and restraint.

Plasma chemistry in nesting leatherback sea turtles (Dermochelys coriacea) from Florida: Understanding the importance of sample hemolysis effects on blood analytes

Plasma chemistry is widely used in diagnostic and research settings in sea turtles. However, plasma discolorations such as hemolysis are often not considered in data interpretation. The objectives of this study were to (1) evaluate the effects of moderate hemolysis on plasma electrolytes, minerals, and proteins using dry chemistry analysis (DCA) and protein electrophoresis from nesting leatherback sea turtles (Dermochelys coriacea) from Florida and to (2) establish blood analyte reference intervals. Twenty-six plasma samples with absence of hemolysis were selected and sub-divided into one non-hemolytic aliquot and an aliquot that was experimentally manipulated to mimic moderate hemolysis. Plasma samples were analyzed for hemoglobin using a handheld photometer; sodium, potassium, chloride, magnesium, calcium, phosphorus, and total protein using DCA; and protein electrophoresis. Packed cell volume and hemoglobin were measured in corresponding whole blood samples. Reference intervals were established. All analytes except calcium and pre-albumin were significantly higher and the calcium:phosphorus and albumin:globulin ratios were significantly lower in hemolytic plasma compared to non-hemolytic plasma. Alpha2-globulins and potassium were the analytes most impacted by hemolysis, averaging 3.3- and 2.0-fold higher in hemolyzed samples, respectively, indicating that (1) hemoglobin migrates into the alpha2-globulin region in this species and (2) notable intracellular potassium is released into plasma with hemolysis. Attempted conversion factors for compensation of hemolysis were considered inaccurate for 4 of 16 analytes due to non-significant regression lines. We also report that PCV provides an estimate of hemoglobin (g/L) using the formula: (2.59 × PCV) + 24.59. Given the spurious effects of hemolysis, the degree of this artifact should be reported with biochemistry data, and samples with moderate to severe hemolysis should be excluded from datasets when interpreting electrolyte, mineral, and protein results. This will ensure accurate data interpretation for individual turtles in rehabilitation or research settings and population-level data relevant to conservation-focused projects.

Structural determinants of CO2-sensitivity in the β connexin family suggested by evolutionary analysis

A subclade of connexins comprising Cx26, Cx30, and Cx32 are directly sensitive to CO2. CO2 binds to a carbamylation motif present in these connexins and causes their hemichannels to open. Cx26 may contribute to CO2-dependent regulation of breathing in mammals. Here, we show that the carbamylation motif occurs in a wide range of non-mammalian vertebrates and was likely present in the ancestor of all gnathostomes. While the carbamylation motif is essential for connexin CO2-sensitivity, it is not sufficient. In Cx26 of amphibia and lungfish, an extended C-terminal tail prevents CO2-evoked hemichannel opening despite the presence of the motif. Although Cx32 has a long C-terminal tail, Cx32 hemichannels open to CO2 because the tail is conformationally restricted by the presence of proline residues. The loss of the C-terminal tail of Cx26 in amniotes was an evolutionary innovation that created a connexin hemichannel with CO2-sensing properties suitable for the regulation of breathing.

REFERENCE INTERVALS FOR ERYTHROCYTE SEDIMENTATION RATE, LACTATE, FIBRINOGEN, HEMATOLOGY, AND PLASMA PROTEIN ELECTROPHORESIS IN CLINICALLY HEALTHY CAPTIVE GOPHER TORTOISES ( GOPHERUS POLYPHEMUS)

Currently available tests for the diagnosis of inflammatory disease in reptiles are limited and poorly sensitive. However, a number of hematological and plasma biochemical analytes are validated in the diagnosis of inflammation in mammals. The objective of this study was to establish reference intervals for erythrocyte sedimentation rate, lactate, heat-precipitated fibrinogen, hematology, and plasma protein electrophoresis based on total protein by biuret method in 23 clinically healthy, captive gopher tortoises ( Gopherus polyphemus) after successful rehabilitation and to determine differences by age, sex, and season. In order to investigate biological differences, samples were collected in April, July, and November. There were no sex differences in any measured analyte; however, there were significant differences by age and season. Immature animals (<2 kg) had significantly higher total protein, albumin : globulin ratio, pre-albumin, albumin, and α-1 globulin than adults. Tortoises sampled in the spring season had significantly higher total solids (refractometer) and lower eosinophils compared with animals sampled in the summer. Further investigation is required to determine the clinical utility of these analytes in the diagnosis of inflammation in this species.

Chelonid Alphaherpesvirus 5 DNA in Fibropapillomatosis-Affected Chelonia mydas

Fibropapillomatosis is a panzootic and chronic disease among Chelonia mydas-usually associated with anthropogenic impacts. This study contributes towards understanding fibropapillomatosis implications for C. mydas populations as a reflector of environmental quality, via prevalence and histological, molecular and blood analyses at a World Heritage site in southern Brazil. Sixty-three juvenile C. mydas (31.3-54.5 cm curved carapace length-CCL) were sampled during two years. Eighteen specimens (~ 29%) had tumours (which were biopsied), while 45 had none. Degenerative changes in the epidermis and Chelonid alphaherpesvirus 5 DNA detection with three variants support a herpesvirus infection. Phylogenetic analysis indicated that variants A and B were similar to a herpesvirus lineage from the Atlantic group, but variant C was similar to a herpesvirus from the eastern Pacific lineage and represents the first published case for marine turtles off Brazil. Significantly lower levels of seven blood parameters, but greater numbers of eosinophils, were observed in tumour-afflicted animals. These observations were attributed to metabolism efficiencies and/or differences in diet associated with temporal-recruitment bias and disease development, and greater non-specific immune stimulation. While most animals had adequate body condition independent of disease, longer-term studies are required to elucidate any protracted population effects.

Blood biochemistry and haematology of migrating loggerhead turtles (Caretta caretta) in the Northwest Atlantic: reference intervals and intra-population comparisons

We documented blood biochemistry and haematology of healthy loggerhead turtles (Caretta caretta) in the Northwest (NW) Atlantic in order to establish clinical reference intervals (RIs) for this threatened population. Blood samples were analysed from migratory loggerheads captured off the Mid-Atlantic coast of the USA in 2011, 2012, 2013 and 2016 as part of a long-term research program. Blood variables were determined using a point-of-care analyser, and a veterinary diagnostic laboratory service. We calculated 95% RIs with associated 90% confidence intervals (CIs) for each blood variable. We compared results obtained from our study of migratory loggerheads with published data for similarly sized loggerheads resident at a seasonal temperate latitude foraging area. Significant differences in several blood variables between migratory and resident turtles provided insight on energetic and health status during different behavioural states. Temperature was significantly correlated with several blood variables: lactate, pCO₂, sodium, haemoglobin and lactate dehydrogenase. Our assessment of blood chemistry in healthy loggerhead turtles in the NW Atlantic provides a baseline for clinical comparisons with turtles impacted by anthropogenic and environmental threats, and highlights the importance of identifying unique aspects of biochemical and haematological profiles for sea turtles at the intra-population level.

Evaluation of point-of-care analysers for blood gas and clinical chemistry in Hermann's tortoises (Testudo hermanni)

OBJECTIVE

To assess the agreement between point-of-care and laboratory analysers in measuring biochemical and blood gas analytes in venous samples from tortoises and to define preliminary reference intervals for venous blood gas analysis in Hermann's tortoises (Testudo hermanni).

MATERIALS AND METHODS

Jugular venous blood samples from 47 Hermann's tortoises underwent paired analysis with a portable gas analyser (i-STAT 1, Abaxis), a portable chemical analyser (VetScan VS2, Abaxis), and with the respective reference analysers. Agarose gel electrophoresis was used to determine albumin concentrations on 12 specimens. Agreement was evaluated with Bland-Altman plots and regression analysis using the Passing-Bablok method.

RESULTS

Point-of-care analysers had variable agreement with the reference analysers, presenting constant or proportional bias depending on the analyte. Relevant analytes in reptiles, such as ionised and total calcium, had acceptable agreement. The method for determining albumin concentration currently available in both point-of-care and laboratory analysers significantly overestimated albumin concentrations as compared to protein electrophoresis.

CLINICAL SIGNIFICANCE

While the use of POC analysers is extremely advantageous in small animal primary care facilities, agreement between point-of-care and laboratory analysers varies depending on the analyte. For certain analytes, interchangeability of results is limited and specific reference intervals for point-of-care analysers are required. Veterinarians should be aware of the size and the direction of the bias of each analyte.

Venous blood gas in free-living eastern box turtles (Terrapene carolina carolina) and effects of physiologic, demographic and environmental factors

Sustainable wildlife populations depend on healthy individuals, and the approach to determine wellness of individuals is multifaceted. Blood gas analysis serves as a useful adjunctive diagnostic test for health assessment, but it is uncommonly applied to terrestrial reptiles. This study established reference intervals for venous blood gas panels in free-living eastern box turtles (Terrapene carolina carolina, N = 102) from Illinois and Tennessee, and modeled the effects of environmental and physiologic parameters on each blood gas analyte. Blood gas panels included pH, partial pressure of oxygen (pO₂), partial pressure of carbon dioxide (pCO₂), total carbon dioxide (TCO₂), bicarbonate (HCO₃^-), base excess (BE) and lactate. Candidate sets of general linear models were constructed for each blood gas analyte and ranked using an information-theoretic approach (AIC). Season, packed cell volume (PCV) and activity level were the most important predictors for all blood gas analytes (P < 0.05). Elevations in PCV were associated with increases in pCO₂ and lactate, and decreases in pH, pO₂, HCO₃^-, TCO₂ and BE. Turtles with quiet activity levels had lower pH and pO₂ and higher pCO₂ than bright individuals. pH, HCO₃^-, TCO₂ and BE were lowest in the summer, while pCO₂ and lactate were highest. Overall, blood pH was most acidic in quiet turtles with elevated PCVs during summer. Trends in the respiratory and metabolic components of the blood gas panel tended to be synergistic rather than antagonistic, demonstrating that either (1) mixed acid-base disturbances are common or (2) chelonian blood pH can reach extreme values prior to activation of compensatory mechanisms. This study shows that box turtle blood gas analytes depend on several physiologic and environmental parameters and the results serve as a baseline for future evaluation.

Venous blood gases, plasma biochemistry, and hematology of wild-caught common chameleons (Chamaeleo chamaeleon)

The purpose of this study was to determine a wide range of selected hematologic, venous blood gases, and plasma biochemistry analytes in common chameleons (Chamaeleo chamaeleon). Blood samples were collected from the ventral tail vein of 41 common chameleons to determine reference intervals for 30 different blood analytes. The calcium-to-phosphorus ratio, packed cell volume (PCV), refractometric total solids (TS), blood cell counts, and differentials were also determined. The microscopic evaluation of blood smears revealed inclusion bodies in monocytes in 7 of the samples. Females showed significantly higher values of plasma proteins and calcium and cholesterol concentrations and males showed significantly higher values of aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) plasma concentrations. Significant differences were found between similar analytes determined by different testing methodologies in the PCV/hematocrit, electrolytes (sodium, potassium), and plasma proteins [TS, total protein (TP) and albumin]. Blood analytes determined in this study can provide baseline data that may be useful when evaluating the health status of common chameleons, taking into consideration the potential effects of gender and the type of analyzer used.

Hematology and serum biochemistry parameters of captive Chinese alligators (Alligator sinensis) during the active and hibernating periods

The Chinese alligator Alligator sinensis is an endangered freshwater crocodilian species endemic to China. Hematology and serum biochemistry reference range are useful in the assessment and management of animal health condition. In this study, a total of 74 Chinese Alligators (30 males and 44 females) were examined to establish reference range values of hematology and serum biochemistry parameters during the active and hibernating periods. We measured and analyzed 9 hematology and 21 serum biochemistry parameters including 4 serum electrolyte parameters, and described the morphology of different types of blood cells. No statistical differences between the sexes were found for hematology parameter, while significant differences were noted for some serum biochemistry parameters, with males having greater alkaline phosphatase activity level and lower globulin concentration value than females. There were some significant differences between the two different periods with alligators during the active period possessing lower values for mean corpuscular volume, mean corpuscular hemoglobin, total bilirubin and creatine kinase, but higher values for red blood cell and white blood cell counts, monocyte percentage, aspartate aminotransferase, a-amylase, blood urea nitrogen, creatinine, triglycerides, and cholesterol. These baseline data were essential for health condition evaluation and disease diagnosis of this endangered species.

Biochemistry and hematology parameters of the San Cristóbal Galápagos tortoise (Chelonoidis chathamensis)

As part of a planned introduction of captive Galapagos tortoises (Chelonoidis chathamensis) to the San Cristóbal highland farms, our veterinary team performed thorough physical examinations and health assessments of 32 tortoises. Blood samples were collected for packed cell volume (PCV), total solids (TS), white blood cell count (WBC) differential, estimated WBC and a biochemistry panel including lactate. In some cases not all of the values were obtainable but most of the tortoises have full complements of results. Despite a small number of minor abnormalities this was a healthy group of mixed age and sex tortoises that had been maintained with appropriate husbandry. This work establishes part of a scientific and technical database to provide qualitative and quantitative information when establishing sustainable development strategies aimed at the conservation of Galapagos tortoises.

Blood gases, biochemistry and haematology of Galápagos hawksbill turtles (Eretmochelys imbricata)

The hawksbill turtle, Eretmochelys imbricata, is a marine chelonian with a circum-global distribution, but the species is critically endangered and has nearly vanished from the eastern Pacific. Although reference blood parameter intervals have been published for many chelonian species and populations, including nesting Atlantic hawksbills, no such baseline biochemical and blood gas values have been reported for wild Pacific hawksbill turtles. Blood samples were drawn from eight hawksbill turtles captured in near shore foraging locations within the Galápagos archipelago over a period of four sequential years; three of these turtles were recaptured and sampled on multiple occasions. Of the eight sea turtles sampled, five were immature and of unknown sex, and the other three were females. A portable blood analyzer was used to obtain near immediate field results for a suite of blood gas and chemistry parameters. Values affected by temperature were corrected in two ways: (i) with standard formulas and (ii) with auto-corrections made by the portable analyzer. A bench top blood chemistry analyzer was used to measure a series of biochemistry parameters from plasma. Standard laboratory haematology techniques were employed for red and white blood cell counts and to determine haematocrit manually, which was compared to the haematocrit values generated by the portable analyzer. The values reported in this study provide reference data that may be useful in comparisons among populations and in detecting changes in health status among Galápagos sea turtles. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease or environmental disasters.

Blood gases, biochemistry and haematology of Galápagos hawksbill turtles (Eretmochelys imbricata)

The hawksbill turtle, Eretmochelys imbricata, is a marine chelonian with a circum-global distribution, but the species is critically endangered and has nearly vanished from the eastern Pacific. Although reference blood parameter intervals have been published for many chelonian species and populations, including nesting Atlantic hawksbills, no such baseline biochemical and blood gas values have been reported for wild Pacific hawksbill turtles. Blood samples were drawn from eight hawksbill turtles captured in near shore foraging locations within the Galápagos archipelago over a period of four sequential years; three of these turtles were recaptured and sampled on multiple occasions. Of the eight sea turtles sampled, five were immature and of unknown sex, and the other three were females. A portable blood analyzer was used to obtain near immediate field results for a suite of blood gas and chemistry parameters. Values affected by temperature were corrected in two ways: (i) with standard formulas and (ii) with auto-corrections made by the portable analyzer. A bench top blood chemistry analyzer was used to measure a series of biochemistry parameters from plasma. Standard laboratory haematology techniques were employed for red and white blood cell counts and to determine haematocrit manually, which was compared to the haematocrit values generated by the portable analyzer. The values reported in this study provide reference data that may be useful in comparisons among populations and in detecting changes in health status among Galápagos sea turtles. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease or environmental disasters.

A comparison of blood gases, biochemistry, and hematology to ecomorphology in a health assessment of pinfish (Lagodon rhomboides)

Despite the promise of hematological parameters and blood chemistry in monitoring the health of marine fishes, baseline data is often lacking for small fishes that comprise central roles in marine food webs. This study establishes blood chemistry and hematological baseline parameters for the pinfish Lagodon rhomboides, a small marine teleost that is among the most dominant members of near-shore estuarine communities of the Atlantic Ocean and Gulf of Mexico. Given their prominence, pinfishes are an ideal candidate species to use as a model for monitoring changes across a wide range of near-shore marine communities. However, pinfishes exhibit substantial morphological differences associated with a preference for feeding in primarily sea-grass or sand dominated habitats, suggesting that differences in the foraging ecology of individuals could confound health assessments. Here we collect baseline data on the blood physiology of pinfish while assessing the relationship between blood parameters and measured aspects of feeding morphology using data collected from 37 individual fish. Our findings provide new baseline health data for this important near shore fish species and find no evidence for a strong linkage between blood physiology and either sex or measured aspects of feeding morphology. Comparing our hematological and biochemical data to published results from other marine teleost species suggests that analyses of trends in blood value variation correlated with major evolutionary transitions in ecology will shed new light on the physiological changes that underlie the successful diversification of fishes.

Assessment of ground transportation stress in juvenile Kemp's ridley sea turtles (Lepidochelys kempii)

Sea turtle rehabilitation centres frequently transport sea turtles for long distances to move animals between centres or to release them at beaches, yet there is little information on the possible effects of transportation-related stress ('transport stress') on sea turtles. To assess whether transport stress is a clinically relevant concern for endangered Kemp's ridley sea turtles (Lepidochelys kempii), we obtained pre-transport and post-transport plasma samples from 26 juvenile Kemp's ridley sea turtles that were transported for 13 h (n = 15 turtles) or 26 h (n = 11 turtles) by truck for release at beaches. To control for effects of handling, food restriction and time of day, the same turtles were also studied on 'control days' 2 weeks prior to transport, i.e. with two samples taken to mimic pre-transport and post-transport timing, but without transportation. Blood samples were analysed for nine clinical health measures (pH, pCO2, pO2, HCO3, sodium, potassium, ionized calcium, lactate and haematocrit) and four 'stress-associated' parameters (corticosterone, glucose, white blood cell count and heterophil-to-lymphocyte ratio). Vital signs (heart rate, respiratory rate and cloacal temperature) were also monitored. Corticosterone and glucose showed pronounced elevations due specifically to transportation; for corticosterone, this elevation was significant only for the longer transport duration, whereas glucose increased significantly after both transport durations. However, clinical health measures and vital signs showed minimal or no changes in response to any sampling event (with or without transport), and all turtles appeared to be in good clinical health after both transport durations. Thus, transportation elicits a mild, but detectable, adrenal stress response that is more pronounced during longer durations of transport; nonetheless, Kemp's ridley sea turtles can tolerate ground transportation of up to 26 h in good health. These results are likely to depend on specific transportation and handling protocols.

Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser

The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3 (-)), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F 2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. Lastly, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.

Health condition of juvenile Chelonia mydas related to fibropapillomatosis in southeast Brazil

Packed cell volume (PCV), plasma biochemistry, visual body condition (BC), and calculated body condition index (BCI) were evaluated in 170 wild juvenile green sea turtles Chelonia mydas from an aggregation in the effluent canal of a steel mill in Brazil. Occurrence of cutaneous fibropapillomatosis (FP) was observed in 44.1% of the animals examined. BCI alone did not differ significantly between healthy animals and those afflicted with FP. However, all turtles with low BCI were severely afflicted and were uremic, hypoglycemic, and anemic in relation to healthy animals. Severe FP was not always reflected by a poor health condition of the individual. Clinical evaluation and plasma biochemistry indicated that most animals afflicted with FP were in good health condition. Differences in FP manifestations and associated health conditions in different geographic regions must be assessed by long-term health monitoring programs to help define priorities for conservation efforts.

Development of a Summarized Health Index (SHI) for use in predicting survival in sea turtles

Veterinary care plays an influential role in sea turtle rehabilitation, especially in endangered species. Physiological characteristics, hematological and plasma biochemistry profiles, are useful references for clinical management in animals, especially when animals are during the convalescence period. In this study, these factors associated with sea turtle surviving were analyzed. The blood samples were collected when sea turtles remained alive, and then animals were followed up for surviving status. The results indicated that significantly negative correlation was found between buoyancy disorders (BD) and sea turtle surviving (p < 0.05). Furthermore, non-surviving sea turtles had significantly higher levels of aspartate aminotranspherase (AST), creatinine kinase (CK), creatinine and uric acid (UA) than surviving sea turtles (all p < 0.05). After further analysis by multiple logistic regression model, only factors of BD, creatinine and UA were included in the equation for calculating summarized health index (SHI) for each individual. Through evaluation by receiver operating characteristic (ROC) curve, the result indicated that the area under curve was 0.920 ± 0.037, and a cut-off SHI value of 2.5244 showed 80.0% sensitivity and 86.7% specificity in predicting survival. Therefore, the developed SHI could be a useful index to evaluate health status of sea turtles and to improve veterinary care at rehabilitation facilities.

Lactated Ringer's solution or 0.9% sodium chloride as fluid therapy in pigeons (Columba livia) submitted to humerus osteosynthesis

The study aimed to compare the effects of intraosseous infusion of lactated Ringer's and 0.9% sodium chloride solutions on the electrolytes and acid-base balance in pigeons submitted to humerus osteosynthesis. Eighteen pigeons were undergoing to isoflurane anesthesia by an avalvular circuit system. They were randomly assigned into two groups (n=9) receiving lactated Ringer's solution (LR) or 0.9% sodium chloride (SC), in a continuous infusion rate of 20mL/kg/h, by using an intraosseous catheter into the tibiotarsus during 60-minute anesthetic procedure. Heart rate (HR), and respiratory rate (RR) were measured every 10 min. Venous blood samples were collected at 0, 30 and 60 minutes to analyze blood pH, PvCO2, HCO3 -, Na+ and K+. Blood gases and electrolytes showed respiratory acidosis in both groups during induction, under physical restraint. This acidosis was evidenced by a decrease of pH since 0 min, associated with a compensatory response, observed by increasing of HCO3 - concentration, at 30 and 60 min. It was not observed any changes on Na+ and K+ serum concentrations. According to the results, there is no reason for choosing one of the two solutions, and it could be concluded that both fluid therapy solutions do not promote any impact on acid-base balance and electrolyte concentrations in pigeons submitted to humerus osteosynthesis.

Blood gases, biochemistry and haematology of Galápagos marine iguanas (Amblyrhynchus cristatus)

The marine iguana, Amblyrhynchus cristatus, is an iconic lizard endemic to the Galápagos Islands of Ecuador, but surprisingly little information exists on baseline health parameters for this species. We analysed blood samples drawn from 35 marine iguanas captured at three locations on San Cristóbal Island. A portable blood analyser (iSTAT) was used to obtain near-immediate field results for pH, lactate, partial pressure of O2, partial pressure of CO2, bicarbonate (HCO3 (-)), percentage O2 saturation, haematocrit, haemoglobin, sodium, potassium, ionized calcium and glucose. Parameter values affected by temperature were auto-corrected by the iSTAT. Standard laboratory haematology techniques were employed for differential white blood cell counts and haematocrit determination; resulting values were also compared with the haematocrit values generated by the iSTAT. Body temperature, heart rate, respiratory rate and body measurements were also recorded. Body length was positively correlated with several blood chemistry values (HCO3 (-) and glucose) and two haematology parameters (haemoglobin and manually determined haematocrit). A notable finding was the unusually high blood sodium level; the mean value of 178 mg/dl is among the highest known for any reptile. This value is likely to be a conservative estimate because some samples exceeded the maximal value the iSTAT can detect. For haematocrit determination, the iSTAT blood analyser yielded results significantly lower than those obtained with high-speed centrifugation. The values reported in this study provide baseline data that may be useful in comparisons among populations and in detecting changes in health status among marine iguanas affected by natural disturbances or anthropogenic threats. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease.

Exertional Myopathy in a Juvenile Green Sea Turtle (Chelonia mydas) Entangled in a Large Mesh Gillnet

A juvenile female green sea turtle (Chelonia mydas) was found entangled in a large mesh gillnet in Pamlico Sound, NC, and was weak upon presentation for treatment. Blood gas analysis revealed severe metabolic acidosis and hyperlactatemia. Plasma biochemistry analysis showed elevated aspartate aminotransferase and creatine kinase, marked hypercalcemia, hyperphosphatemia, and hyperkalemia. Death occurred within 24 hours of presentation despite treatment with intravenous and subcutaneous fluids and sodium bicarbonate. Necropsy revealed multifocal to diffuse pallor of the superficial and deep pectoral muscles. Mild, multifocal, and acute myofiber necrosis was identified by histopathological examination. While histological changes in the examined muscle were modest, the acid-base, mineral, and electrolyte abnormalities were sufficiently severe to contribute to this animal’s mortality. Exertional myopathy in reptiles has not been well characterized. Sea turtle mortality resulting from forced submergence has been attributed to blood gas derangements and seawater aspiration; however, exertional myopathy may also be an important contributing factor. If possible, sea turtles subjected to incidental capture and entanglement that exhibit weakness or dull mentation should be clinically evaluated prior to release to minimize the risk of delayed mortality. Treatment with appropriate fluid therapy and supportive care may mitigate the effects of exertional myopathy in some cases.