EFFECTS OF RANAVIRUS INFECTION OF RED-EARED SLIDERS (TRACHEMYS SCRIPTA ELEGANS) ON PLASMA PROTEINS

Chelonian challenge: three alien species from North America are moving their reproductive boundaries in Central Europe

Biological invasions by alien species have substantial economic impacts and are a major driver of the ongoing decline and loss of biodiversity. Through humans, the North American pond slider (Trachemys scripta) has acquired a global distribution over the last decades and is currently listed among the worst invasive reptile species. However, in more recent times, other freshwater chelonian species have increasingly been recorded far outside their native distribution ranges as well, not only on the same continent but also on others. Despite that, the impact of alien chelonians on their respective new ecosystems remains unclear. The long-term effects and severity of impacts of alien populations mostly depend on whether they ultimately succeed in establishing themselves. This is not entirely resolved for chelonians in Central Europe. To answer that, we investigated wild populations of three non-native chelonian species from North America in Germany (Pseudemys concinna, Graptemys pseudogeographica and Trachemys scripta) applying population genetic approaches. We revealed the successful reproduction of all three species in Germany and provide the very first record for the reproduction of P. concinna and G. pseudogeographica in a temperate continental climate zone outside their native distribution. Based on our unambiguous evidence of natural reproduction, we call for dedicated studies to verify how widespread established populations are and to investigate the existing and potential impacts of all three species in a range of ecosystems along a climatic gradient. Such data is urgently needed to revise the current risk assessments of non-native chelonians, especially in Central European countries.

Protein electrophoresis of non-traditional species: A review

EPH has been demonstrated to be a useful tool in companion animals while providing an opportunity to characterize globulinemias, including paraproteinemia. In EPH of non-traditional species, these same applications are important, but the primary use is to gauge the acute-phase and humoral immune responses. This includes the valid quantitation of albumin as well as the examination of fractions reflective of increases in acute-phase reactants and immunoglobulins. Agarose gel EPH and, more recently, capillary zone EPH have been applied to samples from these species. Performing these analyses provides special challenges in the placement of fraction delimits, generation of RIs, and interpretation of results. Recommended as part of routine bloodwork, EPH can also provide key results that are helpful in clinical and field-based health assessments as well as in prognostication.

A testudinid herpesvirus 1 (TeHV1)-associated disease outbreak in a group of Horsfield's tortoises (Testudo horsfieldii)

In spring 2020, a severe disease outbreak with high morbidity and mortality was observed in a collection of 15 Horsfield's tortoises (Testudo horsfieldii). Affected tortoises showed upper respiratory- and gastrointestinal tract signs, including rhinitis and stomatitis. Testudinid herpesvirus 1 (TeHV1) and Mycoplasma spp. were detected by PCR in oral swabs of affected animals. Histological examination of one deceased animal showed intranuclear inclusion bodies typical for herpesvirus infections in liver, spleen and oesophagus. The virus was likely introduced into the collection 2 years earlier by a clinically healthy Horsfield's tortoise that was tested positive for TeHV1 by PCR.

Patterns of infection, origins, and transmission of ranaviruses among the ectothermic vertebrates of Asia

Ranaviral infections, a malady of ectothermic vertebrates, are becoming frequent, severe, and widespread, causing mortality among both wild and cultured species, raising odds of species extinctions and economic losses. This increase in infection is possibly due to the broad host range of ranaviruses and the transmission of these pathogens through regional and international trade in Asia, where outbreaks have been increasingly reported over the past decade. Here, we focus attention on the origins, means of transmission, and patterns of spread of this infection within the region. Infections have been recorded in both cultured and wild populations in at least nine countries/administrative regions, together with mass die-offs in some regions. Despite the imminent seriousness of the disease in Asia, surveillance efforts are still incipient. Some of the viral strains within Asia may transmit across host-taxon barriers, posing a significant risk to native species. Factors such as rising temperatures due to global climate change seem to exacerbate ranaviral activity, as most known outbreaks have been recorded during summer; however, data are still inadequate to verify this pattern for Asia. Import risk analysis, using protocols such as Pandora+, pre-border pathogen screening, and effective biosecurity measures, can be used to mitigate introduction of ranaviruses to uninfected areas and curb transmission within Asia. Comprehensive surveillance using molecular diagnostic tools for ranavirus species and variants will help in understanding the prevalence and disease burden in the region. This is an important step toward conserving native biodiversity and safeguarding the aquaculture industry.

PLASMA CAPILLARY ZONE ELECTROPHORESIS AND PLASMA CHEMISTRY ANALYTES IN TORTOISES (TESTUDO HERMANNI, TESTUDO GRAECA) AND TURTLES (TRACHEMYS SCRIPTA ELEGANS, GRAPTEMYS SPP.) IN FALL

Clinical health checks including blood testing before brumation in fall are an important tool in reptile medicine and help to reduce the risk of complications during brumation. Electrophoresis may be useful for the evaluation of liver cell function and the detection of antigenic stimulation. The goal of this study was to compare species-specific reference intervals for plasma chemistry analytes and capillary zone electrophoresis (CZE) for a variety of pet chelonian species in fall. Lithium heparinized samples were collected from 68 clinically healthy spur-thighed tortoises (Testudo graeca), 79 red-eared sliders (Trachemys scripta elegans), and 30 map turtles (Graptemys spp.) from September to November 2016 and 2017. During the same period, 128 equivalent samples were collected from Hermann's tortoises (Testudo hermanni) and the obtained data was used for comparison. Chemistry analytes were measured from plasma using an autoanalyzer and electrophoresis was carried out by CZE. Significant variations (P < 0.0001) between the species were found for several analytes including total protein, percent albumin, and albumin: globulin ratio, α-, β-, and γ-globulin, alkaline phosphatase, glutamate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, bile acids, creatine kinase, urea, uric acid, inorganic phosphorus, total calcium, and potassium. The variations in albumin (g/l) measured by CZE were also significant (P = 0.0064). No significant variations were detected for sodium levels. The results demonstrate the importance of species-specific reference intervals and provide reference intervals for the plasma chemistry and capillary zone electrophoresis in three chelonian species.

Emerging Infectious Diseases of Chelonians: An Update

Chelonians are increasingly challenged by anthropogenic threats and disease. This article summarizes recent literature and clinical experiences regarding 4 emerging infectious diseases in turtles and tortoises: ranaviruses, cryptosporidiosis, intranuclear coccodiosis of Testudines, and Emydomyces testavorans.

PROTEIN ELECTROPHORESIS OF PLASMA SAMPLES FROM BOA CONSTRICTORS WITH AND WITHOUT REPTARENAVIRUS INFECTION

Reptarenaviruses infect a variety of boid and pythonid snake species worldwide and have been shown to be the cause of inclusion body disease (IBD). Little is known about the correlations between virus infection and clinical disease, as well as the effects of viral infection on the immune system and the blood protein fractions. The goal of this study was to examine the differences in the plasma protein fractions in reptarenavirus reverse transcription polymerase chain reaction (RT-PCR)-negative and -positive tested snakes with and without clinical signs of disease. Blood from a total of 111 boa constrictors (Boa constrictor) was evaluated. Reverse transcription PCRs and H&E staining for inclusion bodies were carried out on each sample for the detection of reptarenavirus, and the plasma protein fractions were evaluated by capillary zone electrophoresis (CZE). Thirty four of the 111 evaluated snakes were positive by RT-PCR and 19 of the 34 showed clinical signs of disease. In comparison with IBD-negative healthy boa constrictors, the positive snakes with clinical signs had significantly lower albumin levels (P = 0.0052), lower A: G ratios (P = 0.0037), and lower α-globulin levels (P = 0.0073), while their γ-globulin levels were significantly higher (P = 0.0004). In the same comparison, clinically healthy arenavirus-positive boas showed only significantly lower α-globulin (P = 0.0124) and higher γ-globulin levels (P = 0.0394). The results of the present study indicate that reptarenavirus infection may influence plasma protein fractions in boa constrictors.

A comparison of thyroid hormone levels and plasma capillary zone electrophoresis in red-eared sliders (Trachemys scripta elegans) and map turtles (Graptemys spp.) depending on season and sex

BACKGROUND

Thyroid hormones and capillary zone electrophoresis are rarely studied in reptile medicine.

OBJECTIVES

The goal of this prospective study was to establish RIs for plasma proteins and thyroid hormones, total tetraiodothyronine (tT4), free T4 (fT4), total triiodothyronine (tT3), and free T3 (fT3), as well as iodine blood levels in red-eared sliders (Trachemys scripta elegans) and map turtles (Graptemys spp.).

METHODS

Variables were measured over 1 ½ years to determine variations depending on sex and season, as well as any correlations between the parameters. A total of 131 blood samples from red-eared sliders and 51 blood samples from map turtles were collected from May 2016 to November 2017. The levels of tT4, fT4, and fT3 were measured using standardized autoanalyzer test systems; tT3 was measured by ELISA and iodine inductively coupled plasma mass spectrometry. Total protein was quantitated using the biuret method, and plasma protein fractions were measured using capillary zone electrophoresis.

RESULTS

The results showed significant variations in thyroid hormone levels and plasma protein fractions depending on sex and season. Total T4 and fT4 concentrations were significantly (P < .05) correlated in both turtle species and sexes in all seasons. Thyroid hormone levels correlated with blood proteins in a few seasons, including a positive correlation between tT4 and fT4 in female red-eared sliders in fall and female map turtles in summer and fall.

CONCLUSIONS

This study demonstrates the importance of considering species, season, and sex variations when interpreting thyroid hormone and plasma protein levels. It also shows that thyroid hormone levels are not always influenced by total protein and albumin.

Advances in Exotic Animal Clinical Pathology

Over the last 10 years, exotic animal clinical pathology has been evolving, improving health assessment in avian, mammal, fish, reptile, and amphibian patients. These advances are reviewed in this article. Species-specific reference intervals for blood parameters are becoming more available (eg, for ionized calcium, endocrine panels, and vitamin D plasmatic concentrations). In addition, new technologies are being developed to facilitate targeted metabolite detection and result acquisition by veterinarians. Novel techniques, biomarkers, and clinical changes related to disease have been described in avian, mammal, fish, reptile and amphibian species. The use of mobile applications may also be helpful.

Evaluation of Comprehensive Coelomic Fluid Analysis through Coelomic Pore Sampling as a Novel Diagnostic Tool in Elasmobranchs

The objectives of this study were to describe a minimally invasive coelomic fluid sampling technique in elasmobranchs, to characterize the coelomic fluid composition in clinically normal and abnormal animals, and to compare findings from wild and managed populations. Fluid was collected via the coelomic pore in 89 individuals from 16 species spanning clinically normal and abnormal patients within a managed population (n = 54), a semi-managed open-lagoon population (n = 18), and a wild population (n = 17). Biochemical and cytological fluid analyses were performed on all samples, and bacterial and fungal culture, protein electrophoresis, and cholesterol electrophoresis were performed on a subset of samples. The presence of a variable volume of colorless to white and clear to slightly turbid coelomic fluid was consistent with a normal finding; however, the cytological and chemical makeup of coelomic fluid was found to provide additional clinically relevant information. The coelomic fluid from some of the abnormal samples (n = 37) contained white blood cells (n = 15) and concurrent bacteria (n = 7), the latter suggestive of bacterial coelomitis. Yolk was identified in both clinically normal and abnormal females. Of the biochemical parameters tested, calcium, chloride, cholesterol, osmolality, phosphorus, salinity, sodium, specific gravity, total protein, and urea nitrogen have clinical utility. Abnormal samples were mostly associated with reproductive disease, but to a lesser extent with coelomitis and hemocoelom. The wild and semi-managed groups had biochemical differences presumably reflective of the higher salinity of ocean water compared with that in the managed habitat. Aerobic bacteria were identified in normal (n = 7) and abnormal (n = 11) animals. Positive bacterial culture without inflammation may be normal. This study contributes to a further understanding of elasmobranch coelomic fluid analysis and its use as a diagnostic modality for the evaluation of elasmobranch health.