A review of welfare indicators for sea turtles undergoing rehabilitation, with emphasis on environmental enrichment

For animals undergoing rehabilitation it is vital to monitor welfare in a way that is feasible, practical, and limits stress to the animal. The industry gold standard is to assess welfare under the Five Domains model, including nutrition, environment, physical health, and behaviour as the first four physical domains and mental domain as the fifth. Feasibility and effectiveness of these domains for assessing welfare of sea turtles undergoing rehabilitation were reviewed and it was determined that the mental state can be best assessed through behavioural changes. A scoping review of the literature was conducted using Scopus and Web of Science to investigate use of environmental enrichment devices (EEDs) as a measure of welfare in sea turtles. Behavioural assessments using EEDs were found to be well-documented; however, most EED studies pertained largely to livestock or zoo animals. Furthermore, studies rarely concentrated on reptiles, and specifically sea turtles. Results also showed that certain welfare assessment methods may be less appropriate for short-term captivity experienced during rehabilitation. Additionally, the hospital environment limits the ability to address some of the domains (ie biosecurity, feasibility, safety of turtle, etc, might be compromised). This review shows that only three of the nine environmental enrichment strategies described in the literature suit the specific requirements of sea turtles in rehabilitation: feeding, tactile, and structural. It is documented that turtles display behaviours that would benefit from EEDs and, therefore, more specific studies are needed to ensure the best welfare outcomes for sea turtles undergoing rehabilitation.

Influence of exercise and fasting on blood parameters in juvenile green turtles (Chelonia mydas): implications for health assessments

This study investigated the influence of exercise and fasting state on haematologic and biochemical parameters in juvenile green turtles (Chelonia mydas). Animals were divided into two groups; one group was fasted for 72 h and one group was fed 1 h prior to exercise. Exercise was induced by repeated righting reflexes and blood values were measured prior to and post-exercise. Prior to exercise, fasted animals showed significantly decreased levels of urea, pH, PVCO2 and HCO3- and significant increases in Cl- and PVO2, compared to fed animals and fasted animals had significantly poorer exercise performance. Following exercise both fasted and fed animals had significant increases in Na+, K+, Cl-, PVCO2, PVO2, urea and lactate and significant decreases in pH and HCO3-. The magnitude of increase in lactate levels was significantly less in fasted animals. Prior to exercise, a significant correlation was calculated in fasted animals between pH and HCO3-. Following exercise, significant correlations were calculated in fed animals between pH and HCO3-, PVCO2 and lactate, and between pH and HCO3- in fasted animals. These results show that analytical method, fasting state and the physiologic changes induced during the intense exercise can affect haematologic and biochemical analytes and these factors should be considered when interpreting results from health assessment of wild animals.

The use of echocardiography as a health assessment tool in green sea turtles (Chelonia mydas)

There are limited techniques available to assess the health of sea turtles as physical examination has little correlation to clinical findings, and blood reference intervals are broad and provide limited prognostic significance. Advances in the portability of ultrasound machines allow echocardiography to be increasingly used in the health assessments of wild animals. This study performed blood analysis and echocardiograms on 11 green sea turtles upon admission to a rehabilitation clinic and six animals before release. Significant differences were seen between groups, with admission animals having significantly smaller diameters of the cavum arteriosum at systole and diastole, smaller E-waves and an increased fractional shortening. Pre-release animals displayed significant increases in the maximum blood velocities of both the pulmonary artery and the left aorta. Significant negative correlations were seen between fractional shortening and uric acid and between the velocity time integral of the pulmonary artery and urea. The pulmonary artery velocity time integral was also significantly correlated to the E wave. Furthermore, there was asynchrony between the cavum arteriosum and the cavum pulmonale and the detection of a parasitic granuloma in the ventricular outflow tract of one animal. Overall, the results suggest that cardiac function in stranded green sea turtles is significantly impaired and that echocardiography has applications in the health assessments of green sea turtles.

In Vivo Biodistribution of Engineered Lipid Microbubbles in Rodents

Maximal resection of intrinsic brain tumors is a major prognostic factor for survival. Real-time intraoperative imaging tools, including ultrasound (US), are crucial for maximal resection of such tumors. Microbubbles (MBs) are clinically used in daily practice as a contrast agent for ultrasound and can be further developed to serve combined therapeutic and diagnostic purposes. To achieve this goal, we have developed novel MBs conjugated to specific ligands to receptors which are overexpressed in brain tumors. These MBs are designed to target a tumor tissue, visualize it, and deliver therapeutic molecules into it. The objective of this study was to assess the biodistribution of the test items: We used MBs labeled with indocyanine green (MB-ICG) for visualization and MBs conjugated to a cyclic molecule containing the tripeptide Arg-Gly-Asp (RGD) labeled with ICG (MB-RGD-ICG) to target brain tumor integrins as the therapeutic tools. Male Sprague Dawley rats received a single dose of each MB preparation. The identification of the MB in various organs was monitored by fluorescence microscopy in anesthetized animals as well as real-time US for brain imaging. Equally sized control groups under identical conditions were used in this study. One control group was used to establish fluorescence background conditions (ICG), and two control groups were used to test autofluorescence from the test items (MBs and MB-RGD). ICG with or without MBs (naked or RGD-modified) was detected in the brain vasculature and also in other organs. The pattern, duration, and intensity of the fluorescence signal could not be differentiated between animals treated with ICG alone and animals treated with microbubbles MBs-ICG or MBs-RGD-ICG. Following MB injection, either naked or combined with RGD, there was a sharp rise in the Doppler signal within seconds of injection in the brain. The signal was mainly located at the choroid plexus, septum pellucidum, and the meninges of the brain. The signal subsided within a few minutes. Injection of saline or ICG alone to respective animals did not result in a similar raised signal. Following a single intravenous administration of MB-ICG and MB-RGD-ICG to rats, the MBs were found to be effectively present in the brain.

In Vivo Toxicity Study of Engineered Lipid Microbubbles in Rodents

Real-time intraoperative imaging for brain tumor surgery is crucial for achieving complete resection. We are developing novel lipid-based microbubbles (MBs), engineered with specific ligands, which are able to interact with the integrins overexpressed in the endothelium of the brain tumor vasculature. These MBs are designed to visualize the tumor and to carry therapeutic molecules into the tumor tissue, preserving the ultrasound acoustic properties of the starting plain lipid MBs. The potential toxicity of this novel technology was assessed in rats by intravenous injections of two doses of plain MBs and MBs engineered for targeting and near-infrared fluorescence visualization at two time-points, 10 min and 7 days, for potential acute and chronic responses in rats [(1) MB, (2) MB-ICG, (3) MB-RGD, and (4) MB-ICG-RGD]. No mortality occurred during the 7-day study period in any of the dosing groups. All animals demonstrated a body weight gain during the study period. Minor, mostly reversible changes in hematological and biochemical analysis were observed in some of the treated animals. All changes were reversible by the 7-day time-point. Histopathology examination in the high-dose animals showed development of foreign body granulomatous inflammation. We concluded that the low-dose tested items appear to be safe. The results allow for proceeding to clinical testing of the product.

Susceptibility of eastern water dragons Intellagama lesueurii lesueurii to Bohle iridovirus

Ranaviruses infect and have been associated with mass mortality events in fish, amphibians and reptiles and are capable of interclass transmission. Eastern water dragons (EWDs), a semi-aquatic squamate, have an overlapping distribution with several species shown to be susceptible to Bohle iridovirus (BIV). However, this species has not been previously investigated, and no known mass mortalities have occurred in wild populations. Here we report the experimental infection of juvenile EWDs with BIV to investigate a water-dwelling lizards' susceptibility to a ranaviral strain present in northern Queensland, Australia. Lizards were exposed via oral inoculation, intramuscular injection, or cohabitation with orally infected lizards. All exposure methods were effective in establishing an infection as demonstrated by skin lesions and pathological changes in the internal organs. Necrosis, haemorrhage and inflammation were observed histologically in the pancreas, liver, spleen, kidney and submucosa of the gastrointestinal tract of BIV-exposed lizards. Variably sized basophilic intracytoplasmic inclusion bodies were observed in the liver of 6/14 BIV-exposed lizards. Virus was isolated from the liver and kidney of all BIV-infected lizards and confirmed with quantitative PCR (qPCR). The outcome of this study demonstrates that juvenile EWDs are susceptible to BIV, thereby adding Australian lizards to the broad host range of ranaviruses. Furthermore, this study provides additional evidence of BIV's ability to infect different classes of ecothermic vertebrates.

Serological survey of Australian native reptiles for exposure to ranavirus

Ranaviruses have been isolated from many ectothermic vertebrates, and serological surveys of both amphibians and reptiles have shown the presence of ranaviral antibodies in a proportion of these populations. An enzyme-linked immunosorbent assay (ELISA) was developed to measure serum antibodies against ranavirus in Australian reptiles. The ELISA was validated with serum from challenge trials with Bohle iridovirus (BIV) in 6 reptilian species. A preliminary sero-survey of northern Queensland riparian reptile fauna (saw-shelled turtles Myuchelys latisternum, Krefft's river turtles Emydura macquarii krefftii, freshwater crocodiles Crocodylus johnstoni, as well as the snakes Boiga irregularis, Dendrelaphis punctulatus, Tropidonophis mairii, Morelia spilota, Liasis childreni and L. fuscus) revealed evidence of past exposure to Bohle iridoviral antigens in part of the population at several locations sampled. Furthermore, in Krefft's river turtles and freshwater crocodiles, a statistically significant trend was apparent for larger reptiles to be more likely to have BIV-reactive sera than smaller individuals. The use of adult tortoise populations as sentinels can assist in monitoring the presence of BIV in northern Australian freshwater streams, and thereby the potential dangers to native fauna from this agent.

An unusual mortality event in Johnstone River snapping turtles Elseya irwini (Johnstone) in Far North Queensland, Australia

BACKGROUND

An unusual mortality event in Johnstone River snapping turtles (Elseya irwini) in Far North Queensland, Australia, occurred during the summer months of December 2014 and January 2015. We report the data collected during the mortality event, including counts of sick and dead animals, clinical appearance and one necropsy.

OUTBREAK DESCRIPTION

Moribund animals appeared lethargic with variable degrees of necrotising dermatitis. Postmortem investigation of one freshly dead animal revealed bacterial and fungal involvement in the skin lesions as well as multifocal fibrinous hepatitis and splenitis and necrotising enteritis with vascular thrombosis. Aeromonas hydrophila was isolated from liver, spleen and skin lesions. All samples tested negative for ranavirus, and water and soil testing for environmental contaminants were negative. All affected E. irwini either died or were euthanased and no other species of animals in the river were affected.

CONCLUSION

Aeromonas hydrophila is ubiquitous in the freshwater environment and although it caused septicaemia in the one individual that was submitted for laboratory diagnosis, the primary aetiology of the outbreak may not have been identified.

Phylogenetic Variation of Chelonid Alphaherpesvirus 5 (ChHV5) in Populations of Green Turtles Chelonia mydas along the Queensland Coast, Australia

Sea turtle fibropapillomatosis (FP) is a disease marked by the proliferation of benign but debilitating cutaneous and occasional visceral tumors, likely to be caused by chelonid alphaherpesvirus 5 (ChHV5). This study presents a phylogeny of ChHV5 strains found on the east coast of Queensland, Australia, and a validation for previously unused primers. Two different primer sets (gB-1534 and gB-813) were designed to target a region including part of the UL27 glycoprotein B (gB) gene and part of UL28 of ChHV5. Sequences obtained from FP tumors found on juvenile green turtles Chelonia mydas (<65 cm curved carapace length) had substantial homology with published ChHV5 sequences, while a skin biopsy from a turtle without FP failed to react in the PCRs used in this study. The resulting sequences were used to generate a neighbor-joining tree from which three clusters of ChHV5 from Australian waters were identified: north Australian, north Queensland, and Queensland clusters. The clusters reflect the collection sites on the east coast of Queensland with a definitive north-south trend. Received October 22, 2016; accepted May 7, 2017.

Pathogenesis of Frog Virus 3 (Ranavirus, Iridoviridae) Infection in Wood Frogs (Rana sylvatica)

Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 104.43 pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.

Pathogenicity in six Australian reptile species following experimental inoculation with Bohle iridovirus

Ranaviruses are able to infect multiple species of fish, amphibian and reptile, and some strains are capable of interclass transmission. These numerous potential carriers and reservoir species compound efforts to control and contain infections in cultured and wild populations, and a comprehensive knowledge of susceptible species and life stage is necessary to inform such processes. Here we report on the challenge of 6 water-associated reptiles with Bohle iridovirus (BIV) to investigate its potential pathogenicity in common native reptiles of the aquatic and riparian fauna of northern Queensland, Australia. Adult tortoises Elseya latisternum and Emydura krefftii, snakes Boiga irregularis, Dendrelaphis punctulatus and Amphiesma mairii, and yearling crocodiles Crocodylus johnstoni were exposed via intracoelomic inoculation or co-habitation with infected con-specifics, but none were adversely affected by the challenge conditions applied here. Bohle iridovirus was found to be extremely virulent in hatchling tortoises E. latisternum and E. krefftii via intracoelomic challenge, as demonstrated by distinct lesions in multiple organs associated with specific immunohistochemistry staining and a lethal outcome (10/17) of the challenge. Virus was re-isolated from 2/5 E. latisternum, 4/12 E. krefftii and 1/3 brown tree snakes B. irregularis. Focal necrosis, haemorrhage and infiltration of granulocytes were frequently observed histologically in the pancreas, liver and sub-mucosa of the intestine of challenged tortoise hatchlings. Immunohistochemistry demonstrated the presence of ranavirus antigens in the necrotic lesions and in individual cells of the vascular endothelium, the connective tissue and in granulocytes associated with necrosis or present along serosal surfaces. The outcome of this study confirms hatchling tortoises are susceptible to BIV, thereby adding Australian reptiles to the host range of ranaviruses. Additionally, given that BIV was originally isolated from an amphibian, our study provides additional evidence that interclass transmission of ranavirus may occur in the wild.

Diagnostic capacity for viral haemorrhagic septicaemia virus (VHSV) infection in rainbow trout (Oncorhynchus mykiss) is greatly increased by combining viral isolation with specific antibody detection

Detection of disease specific antibodies in farmed rainbow trout (Oncorhynchus mykiss) has been proposed as an alternative or supplement to the currently approved procedures for diagnosis and surveillance in this species. In samples from natural outbreaks of the disease viral haemorrhagic septicaemia (VHS) at two freshwater farms in southern Denmark serologic testing was used to broaden the diagnostic window from outbreak to diagnosis in the laboratory as compared to traditional procedures of isolation and identification of the virus. The serologic assay clearly increased the chance of detecting present or previous infections where the pathogen could not be isolated by standard methods (indicating older infections where the virus had been cleared). Our data allowed us to monitor the levels of neutralising antibodies in relation to the presence of the virus in fish experiencing two different types of outbreaks at two different farms. By sequence analysis of the viral glycoprotein from selected isolates we found no evidence for escape mutants having developed in the fish showing high titres of neutralising antibodies.

Investigation of ornamental fish entering the EU for the presence of ranaviruses

A survey was performed on ornamental fish imported into the EU to detect viral agents belonging to the genus Ranavirus. The objective was to gain knowledge of the potential for these systemic iridoviruses to gain entry into the EU via international trade in ornamental fish. A total of 208 pooled samples, representing 753 individual fish, were tested. The samples included 13 orders and 37 families, originating from different countries and continents. Tissues from fish that died during or just after transport were collected and examined by standard virological techniques in epithelioma papulosum cyprini cells, by transmission electron microscopy and by PCR for the detection of the major capsid protein and DNA polymerase gene sequences of ranaviruses. Virus was isolated from nine fish species but ranavirus was not identified in those samples. The results suggest that ranaviruses are not highly prevalent in ornamental fish imported into the EU.

Challenge studies of European stocks of redfin perch, Perca fluviatilis L., and rainbow trout, Oncorhynchus mykiss (Walbaum), with epizootic haematopoietic necrosis virus

A challenge model for comparison of the virulence of epizootic haematopoietic necrosis virus (EHNV) to European stocks of redfin perch, Perca fluviatilis L., and rainbow trout, Oncorhynchus mykiss (Walbaum), was tested. The model investigated intraperitoneal (IP), bath and cohabitation routes at 10, 15 and 20 degrees C for 5-6 g fish and 15 degrees C for 20 g perch. In the IP challenges of perch, significant mortality occurred at 15 degrees C and 20 degrees C. In challenge trials for rainbow trout, significant mortalities were observed in IP and bath challenges at 20 degrees C. The mortality observed in IP challenged 20 g perch was not significantly different from that recorded for 6 g fish challenged IP. No significant mortality was observed in any other treatment groups. Re-isolation of ranavirus was confirmed by IFAT and was consistently associated with dead or moribund fish in the trial groups challenged with EHNV. The findings indicate that EHNV does not pose a high risk for wild perch and trout populations in Europe by natural exposure. Mortality appears to be primarily a function of environmental factors, with temperature playing an important role, and not just the presence of the virus in the fish.

[Comparison of methods for detection of an infection with different isolates of infectious haematopoietic necrosis virus (IHNV)]

The infectious haematopoietic necrosis (IHN) is beside the viral haemorrhagic septicemia (VHS) one of the viral fish diseases that have a considerable economic impact on German aquaculture. The measures actually in force are focused on control and spread prevention of the disease within the borders of the European Union (EU). The detection and confirmation of an outbreak is performed according to the pertinent EU legislation which allow the application of methods like the virus neutralisation test (VNT), the immunofluorescence test (IFT) and the enzyme-linked immunosorbent assay (ELISA). Besides the classic virological serology methods, further tests for the identification and confirmation of the fish pathogen like i.e. PCR and DNA probe techniques are recommended by the OIE. To compare diagnostic methods as ELISA, cell cultivation and RT-PCR, rainbow trout of the strain "Isle of Man" were infected with six IHNV strains. Samples were taken on day 7 (viraemia period) and at the day 28 of the trial. The ground organs were inoculated into EPC cells (Epithelioma papulosum Cyprini cells) and examined by ELISA as well as after RNA extraction by RT-PCR. Besides the determination of the isolate as well as the virulence for 20 g trout, significant differences in the demonstration of the viruses were observed. While the RT-PCR demonstrated to be the most sensitive method, antigen ELISA and virus cultivation results showed in dependence of the IHNV isolate that not all viruses were identifiable under the chosen experimental condition in the same manner.