Environmental temperature influences ophidiomycosis progression and survival in experimentally challenged prairie rattlesnakes (Crotalus viridis).

Ophidiomycosis is a prevalent and intermittently pervasive disease of snakes globally caused by the opportunistic fungal pathogen, Ophidiomyces ophidiicola. Host response has yet to be fully explored, including the role of temperature in disease progression and hematologic changes. This study enrolled twelve adult prairie rattlesnakes (Crotalus viridis) in an experimental challenge with O. ophidiicola at two temperatures, 26°C (n = 6) and 20°C (n = 6). Each temperature cohort included four inoculated and two control snakes. Assessments involving physical exams, lesion swabbing, and hematology were performed weekly. Differences were observed between inoculated and control snakes in survival, behavior, clinical signs, ultraviolet (UV) fluorescence, hematologic response, and histologic lesions. All inoculated snakes held at 20°C were euthanized prior to study end date due to severity of clinical signs while only one inoculated animal in the 26°C trial met this outcome. In both groups, qPCR positive detection preceded clinical signs with regards to days post inoculation (dpi). However, the earliest appearance of gross lesions occurred later in the 20°C snakes (20 dpi) than the 26°C snakes (13 dpi). Relative leukocytosis was observed in all inoculated snakes and driven by heterophilia in the 20°C snakes, and azurophilia in the 26°C group. Histologically, 20°C snakes had more severe lesions, a lack of appropriate inflammatory response, and unencumbered fungal proliferation and invasion. In contrast, 26°C snakes had marked granulomatous inflammation with encapsulation of fungi and less invasion and dissemination. The results of this study identified that O. ophidiicola-infected rattlesnakes exposed to lower temperatures have decreased survival and more robust hematologic change, though minimal and ineffective inflammatory response at site of infection. Ophidiomycosis is a complex disease with host, pathogen, and environmental factors influencing disease presentation, progression, and ultimately, survival. This study highlighted the importance of temperature as an element impacting the host response to O. ophidiicola.

Plasma electrophoresis profiles of Blanding's turtles (Emydoidea blandingii) and influences of month, age, sex, health status, and location.

Baseline plasma electrophoresis profiles (EPH) are important components of overall health and may aid in the conservation and captive management of species. The aim of this study was to establish plasma protein fractions for free-ranging Blanding's turtles (Emydoidea blandingii) and evaluate differences due to age class (adult vs. sub-adult vs. juvenile), sex (male, female, or unknown), year (2018 vs. 2019), month (May vs. June vs. July), health status, and geographical location (managed vs. unmanaged sites). Blood samples were obtained from 156 Blanding's turtles in the summer of 2018 and 129 in 2019 at two adjacent sites in Illinois. Results of the multivariate analysis demonstrated that age class, sex, year, month, health status, and geographical location all contributed to the variation observed in free-ranging populations. Adult females had the highest concentration of many protein fractions, likely associated with reproductive activity. Juveniles had lower protein concentrations. Temperature and rainfall differences between years impacted concentrations between 2018 and 2019, while May and June of both years saw higher levels in some protein fractions likely due to peak breeding and nesting season. Individuals with evidence of trauma or disease also showed increased plasma protein fractions when compared to those that were considered healthy. The two sites showed a wide/large variation over the two years. All of these factors emphasize the importance of considering multiple demographic or environmental factors when interpreting the EPH fractions. Establishing ranges for these analytes will allow investigation into disease prevalence and other environmental factors impacting this endangered species.

Detection of a novel herpesvirus associated with squamous cell carcinoma in a free-ranging Blanding's turtle.

The spread of both infectious and noninfectious diseases through wildlife populations is of increasing concern. Neoplastic diseases are rarely associated with population-level impacts in wildlife; however, impacts on individual health can be severe and might reflect deteriorating environmental conditions. An adult male free-ranging Blanding's turtle (Emydoidea blandingii) originally captured in 2005 and deemed healthy, was recaptured in 2018 with a 1 × 1.5 cm intra-oral broad-based right mandibular mass. An excisional biopsy was performed, and histopathology revealed squamous cell carcinoma (SCC). Consensus herpesvirus PCR identified a novel herpesvirus (proposed name Emydoidea herpesvirus 2 [EBHV-2]) within the tumor. EBHV-2 shares 85% sequence homology with Terrapene herpesvirus 2 (TerHV-2), a herpesvirus linked to fibropapillomas in eastern box turtles (Terrapene carolina carolina). Virus-associated fibropapillomas have been identified in multiple marine turtle species and have had debilitating effects on their populations, but to date, virus-associated SCCs are rarely reported.

CHARACTERIZING THE EPIDEMIOLOGY OF HISTORIC AND NOVEL PATHOGENS IN BLANDING'S TURTLES (EMYDOIDEA BLANDINGII).

Pathogens such as herpesviruses, Mycoplasma spp., and frog virus 3-like ranavirus have contributed to morbidity and mortality in many species of free-living and zoo-maintained chelonians. However, their prevalence is understudied in Blanding's turtles (Emydoidea blandingii) across North America. To assess the presence of these pathogens, Blanding's turtles were sampled in Lake County, Illinois, in 2017 (N = 213) and 2018 (N = 160). DNA from cloacal-oral swabs was assayed for four ranaviruses, three Mycoplasma spp., two Salmonella spp., Emydoidea herpesvirus 1 (EBHV1), and tortoise intranuclear coccidiosis (TINC) using a multiplex quantitative polymerase chain reaction (qPCR). Pathogens were most frequently detected in adult turtles (n = 25) and rarely in subadults (n = 2) or juveniles (n = 1). EBHV1 was detected in 22 individuals with no clinical signs of illness, most (n = 20) occurring in the month of May (P < 0.0001). EBHV1 cases at one study site significantly clustered within the same 0.64-km area from 17 to 22 May 2017 (P < 0.0001) and 14 to 15 May 2018 (P = 0.0006). Individuals were rarely positive for Salmonella typhimurium (n = 6). A novel Mycoplasma sp. sharing high homology with other emydid Mycoplasma spp. was detected in one turtle with nasal discharge. Neither TINC nor any ranaviruses were detected. Continued monitoring of this population and habitat may facilitate identification of risk factors for pathogen occurrence and clarify the impact of infectious diseases on Blanding's turtle conservation outcomes.

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

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