Journal of Wildlife Diseases最新文献

We necropsied a red fox (Vulpes vulpes) with gross and histologic lesions suggestive of leptospirosis, with intralesional argyrophilic bacteria. Real-time PCR detected Leptospira spp. in multiple organs. We identified Leptospira interrogans related to the Australis serogroup by typing the 16S rRNA and Lfb1 genes and by multilocus sequence typing.

The Mexican long-nosed nine-banded armadillo (Dasypus mexicanus) has continued to expand its range since it was first documented in Texas, US, in the mid-1800s. It dispersed north and east and was found in Missouri, USA, starting in the 1980s. This species is known to contract leprosy, also known as Hansen's disease, caused by Mycobacterium leprae. Infected armadillos are considered to be a zoonotic source of leprosy in the US. A recent case (2021) of leprosy in a native Missourian who had a history of contacts with armadillos appears to have been locally acquired. However, no data were available on the presence or prevalence of leprosy in wild armadillos from Missouri. We sampled various tissues from 64 armadillos, 39 road killed and 25 hunter killed/culled, from southwestern and central Missouri in summer 2022 to determine the local prevalence of M. leprae. Two animals were PCR positive for M. leprae, providing evidence that this pathogen is moving northward along with the range expansion of Mexican long-nosed armadillos.

This study investigated the prevalence of widely researched amphibian pathogens within the Rhyacotritonidae, a salamander family endemic to the Pacific Northwest of the USA. We tested skin swabs (n=309) from southern torrent salamanders (Rhyacotriton variegatus) in northern California, USA, for the presence of three pathogens: Batrachochytrium dendrobatidis, Batrachochytrium salamandrivorans, and ranavirus (frog virus 3-like). Using quantitative PCR assays, we detected ranavirus DNA in 16% of swabs but did not detect either Batrachochytrium spp. Prevalence of ranavirus ranged from 0% to 40%, and was significantly different across nine sites in Humboldt and Del Norte counties. Viral load was significantly and positively associated with the water temperature of the microhabitat. Nevertheless, overall viral loads were generally low (none higher than 782 viral particles per swab), and we did not observe any animals exhibiting clinical signs typically associated with ranavirus disease. Further research is needed to determine if this species can develop ranavirus-associated disease.

Lead (Pb) exposure is a global concern because of its harmful effects on the environment, animals, and humans. Although research on Pb poisoning in humans and avian species is extensive, similar literature on mammalian carnivores is limited. Only two reports of suspected Pb poisoning in captive cheetahs (Acinonyx jubatus) exist, and none in wild cheetahs. We quantified cumulative life exposure to Pb in 62 cheetahs (33 males, 29 females) and 11 (unknown sex) leopards (Panthera pardus). Cheetahs were grouped according to time spent in captivity: wild (>10% of life in the wild) and captive (10-100% of life in captivity); all leopards were wild. Bone Pb concentration (BLC) was measured in tibias to assess the effects of time in captivity, age, and sex on Pb exposure. Lead was detected in all cheetah and leopard tibias. Mean BLC was 1.11±1.92 mg/kg for all cheetahs, with a significantly higher mean in captive (1.57±2.25 mg/kg) versus wild (0.27±0.39 mg/kg) cheetahs. Time in captivity had a significant effect on BLC, with BLC increasing with years spent in human care. Wild leopards had a higher BLC than wild cheetahs, with a mean BLC of 1.02±1.56 mg/kg. Higher BLC in captive than wild cheetahs was attributed to Pb exposure from the ammunition used to shoot ungulates for their diet. Increased exposure in wild leopards might be attributable to opportunistic scavenging, a behavior not typically seen in wild cheetahs. This study highlights the need for non-Pb ammunition options in support of conservation, animal welfare, and ultimately human health.

We investigated the prevalence, cyst density, and any associated pathologic changes of Besnoitia spp. in the testis, peritesticular structures, and udder skin of migratory caribou (Rangifer tarandus). Possible risk factors for infection, cyst density, and inflammation were investigated. Samples from 149 male and 229 female caribou were collected from seven different herds across Canada, Alaska (US), and Greenland, 2007-09. Biopsies were taken from the udder skin in females and from the epididymis, scrotal skin, testis (seminiferous tubules and tunica albuginea), and spermatic cord in males. The cyst density (cysts per square millimeters) of Besnoitia spp. in each tissue, as well as the type of associated inflammation, were determined by histopathologic examination. Individual (age class) and environmental (season and herd) risk factors were investigated for infection, cyst density, and inflammation. Besnoitia spp. cysts were detected in 22.2, 20.4, 11.2, 31.3, 10.4, and 8.0% of the sections of epididymis, scrotal skin, seminiferous tubules, spermatic cord, tunica albuginea, and udder skin, respectively. The median cyst densities varied from 0.07 cysts/mm2 in the seminiferous tubules to 1.02 cysts/mm2 in the udder skin. Age class and season were risk factors for infection, so adults and subadults were more at risk than calves, and infection was more prevalent in the fall months (September to December) relative to other seasons. Subadults, however, demonstrated a higher cyst density compared with adults and calves. During the winter months, a higher risk of inflammation was present compared with other seasons. Overall, the intensity of inflammation was light to mild, and both pericystic and concomitant inflammation were commonly present. Further research should determine whether these parasitic cysts and the associated inflammation influence the functionality of the testis, peritesticular structures, and udder and thus reproduction.

Highly pathogenic avian influenza (HPAI) H5Nx virus clade 2.3.4.4b has impacted wild birds and mammals in Canada since late 2021, including at-risk species. We compared detections and conservation status to highlight the need to integrate disease surveillance with conservation planning when assessing risks and to guide management.

Emydomyces testavorans is a recently described fungus associated with significant shell disease in chelonians, including Illinois state-endangered Blanding's turtles (Emydoidea blandingii). Characterizing the epidemiology of this pathogen requires accurate detection; however, E. testavorans is challenging to detect and optimal antemortem sampling strategies have not been identified. In total, 90 juvenile Blanding's turtles from two populations naturally infected with E. testavorans were used to determine the detection performance of different testing approaches and establish optimal sampling strategies in the context of commonly encountered clinical and management scenarios. Turtles received comprehensive physical examinations and computed tomography scans to document grossly apparent and/or radiographic shell lesions. Multiple sample types were tested for E. testavorans via quantitative PCR (qPCR), including shell swabs, combined cloacal-oral swabs, combined cloacal-oral-shell swabs (COSSs) swabs, and tank water samples. Latent class modeling was used to determine the sensitivity and specificity of each detection method in the absence of a gold standard test. Using multiple tests often increases information available to decision-makers; therefore, sensitivity, specificity, and positive and negative predictive values were calculated for two E. testavorans detection methods interpreted either in series or in parallel. Latent class modeling demonstrated that COSS and water qPCRs were highly sensitive (98.0 and 94.0%, respectively) and adequately specific (74.9 and 88.3%, respectively) for E. testavorans; thus, these testing methods are recommended for routine surveillance where use of multiple methods is not possible. In wild and head-started Blanding's turtle populations where false negatives are costly, qPCR testing of two COSS samples interpreted in parallel maximized sensitivity (sensitivity=100%, specificity=56.1%) and is recommended for E. testavorans surveillance when multiple tests are available. This study provides objective measures to guide effective E. testavorans testing and inform future epidemiologic studies, support chelonian medicine, and empower conservation managers, ultimately safeguarding turtle health in managed care and wild settings.

Effective biosecurity practices are essential for mitigating the risks of pathogen transmission in human-wildlife interactions, yet it is unclear how infection control policies are put into action by those working with wildlife. We evaluated biosecurity practices among professionals working with cervids in the US and Canada via an electronic survey conducted between March 2024 and June 2024. The objectives were to identify pathogens of concern, describe current biosecurity protocols, evaluate the appropriateness of disinfecting practices, and explore associations between biosecurity practices and factors such as profession, regional disease status, and the nature of interactions with cervids. Survey respondents were primarily ecologists or biologists (47%), veterinarians (46%), and managers or wildlife capture professionals lacking those backgrounds (6%). Respondents identified chronic wasting disease (CWD) and SARS-CoV-2 as primary pathogens of concern, with CWD being the most frequently targeted for disinfection, even in nonendemic areas. Although most respondents indicated the use of biosecurity protocols, adherence was inconsistent, particularly in free-living settings. Professionals working with captive cervids were significantly more likely to consistently follow biosecurity protocols than those working exclusively with free-living cervids. Use of personal protective equipment was common. Veterinarians were more likely than managers lacking an ecology, biology, or veterinary background to disinfect cervid sampling equipment between individual animals. Those working in regions where CWD was endemic were more likely to have formal biosecurity policies and cleaning and disinfection protocols compared with those in nonendemic areas. Our study also identified biosecurity protocol gaps, with some respondents using ineffective disinfectants or suboptimal concentrations against reported pathogens of concern. These findings highlight the need for standardized, evidence-based guidelines when developing and implementing cervid biosecurity protocols, particularly regarding effective disinfectant use.

We present a case of multicentric lymphoma in a wild chilla fox (Lycalopex griseus) found dead after a dog attack. Mesenteric, bronchial, submandibular, and popliteal lymph nodes and the thymus were affected. Histopathology and immunohistochemistry confirmed a T-cell lymphoma with a histiocytic component.

Ranaviruses (Iridoviridae) are highly virulent emerging pathogens that affect a wide range of ectotherms, including fishes, amphibians, and reptiles. In turtles, ranaviruses have contributed to deadly epizootic events in wild and captive populations. Despite ranaviruses being pathogens of major concern, their transmission is poorly understood in reptiles and the potential for vertical transmission (from mother to offspring) remains unaddressed. We investigated vertical transmission of ranavirus in eastern box turtles (Terrapene carolina carolina) by screening 25 reproductive females and their offspring (n=74). We collected samples from adult females up to four times during the 2022 reproductive season and, in some cases, for up to 3 yr prior. We collected samples from offspring at hatch in 2022 and approximately 8 mo later. We documented seven reproductive females with positive ranavirus detections, although no females tested positive at more than one time point and all detections occurred 2-3 yr before reproductive monitoring in 2022. We documented nine hatchlings from six clutches with positive ranavirus detections, seven of which were produced by four females without a documented history of ranavirus detection. None of the ranavirus-positive hatchlings exhibited clinical signs of disease throughout an 8-mo captive rearing period; five of seven initially positive hatchlings were negative at release, and all survived until release. Hatchlings in which we detected ranavirus exhibited low viral loads, and we found no evidence that they transmitted the virus to their clutchmates during captive rearing. Collectively, our results suggest that vertical transmission of ranavirus is possible in box turtles, but we found no evidence that the low viral loads we observed resulted in disease. Further research is needed to determine the precise mode of vertical transmission in turtles and to understand the potential individual and population-level effects of maternally derived infections.