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Viral infections were investigated in American black bears (Ursus americanus) from Nevada and northern California with and without idiopathic encephalitis. Metagenomics analyses of tissue pools revealed novel viruses in the genera Circoviridae, Parvoviridae, Anelloviridae, Polyomaviridae, and Papillomaviridae. The circovirus and parvovirus were of particular interest due to their potential importance as pathogens. We characterized the genomes of these viruses and subsequently screened bears by PCR to determine their prevalence. The circovirus (Ursus americanus circovirus, UaCV) was detected at a high prevalence (10/16, 67%), and the chaphamaparvovirus (Ursus americanus parvovirus, UaPV) was found in a single bear. We showed that UaCV is present in liver, spleen/lymph node, and brain tissue of selected cases by in situ hybridization (ISH) and PCR. Infections were detected in cases of idiopathic encephalitis and in cases without inflammatory brain lesions. Infection status was not clearly correlated with disease, and the significance of these infections remains unclear. Given the known pathogenicity of a closely related mammalian circovirus, and the complex manifestations of circovirus-associated diseases, we suggest that UaCV warrants further study as a possible cause or contributor to disease in American black bears.

In North America, epizootic pneumonia is a devastating, population-limiting disease of bighorn sheep (Ovis canadensis) (1-5). Anecdotal and experimental evidence suggests that in at least some instances, this disease may [...]

Conservation biologists have increasingly used translocations to mitigate population declines and restore locally extirpated populations. Genetic data can guide the selection of source populations for translocations and help evaluate restoration success. Bighorn sheep (Ovis canadensis) are a managed big game species that suffered widespread population extirpations across western North America throughout the early 1900s. Subsequent translocation programs have successfully re‐established many formally extirpated bighorn herds, but most of these programs pre‐date genetically informed management practices. The state of Nevada presents a particularly well‐documented case of decline followed by restoration of extirpated herds. Desert bighorn sheep (O. c. nelsoni) populations declined to less than 3,000 individuals restricted to remnant herds in the Mojave Desert and a few locations in the Great Basin Desert. Beginning in 1968, the Nevada Department of Wildlife translocated ~2,000 individuals from remnant populations to restore previously extirpated areas, possibly establishing herds with mixed ancestries. Here, we examined genetic diversity and structure among remnant herds and the genetic consequences of translocation from these herds using a genotyping‐by‐sequencing approach to genotype 17,095 loci in 303 desert bighorn sheep. We found a signal of population genetic structure among remnant Mojave Desert populations, even across geographically proximate mountain ranges. Further, we found evidence of a genetically distinct, potential relict herd from a previously hypothesized Great Basin lineage of desert bighorn sheep. The genetic structure of source herds was clearly reflected in translocated populations. In most cases, herds retained genetic evidence of multiple translocation events and subsequent admixture when founded from multiple remnant source herds. Our results add to a growing literature on how population genomic data can be used to guide and monitor restoration programs. [ABSTRACT FROM AUTHOR]

The article reports on the development a polymerase chain reaction (PCR) assay specific for Mannheimia haemolytica (M.h.) to determine its presence in the pneumonic lungs of bighorn sheep during the 2009-10 outbreaks in three states. M. h. was detected in 77% of archived pneumonic lung tissues that were negative by culture. Collective results show that culture-based methods are unreliable for detecting M. h., and that leukotoxin-positive M.h. was a predominant agent in the outbreaks.

An introduction to a special supplement to the "Journal of Wildlife Diseases" devoted to advances and improvements in wildlife welfare is presented.

A letter to the editor is presented in response to the article "American Veterinary Medical Association policy on trap-neuter-vaccinate-return programs for free-ranging cats (left)" by G.R. Weedon and others published in a 2015 issue.

Wildlife may be infected with a high diversity of piroplasms and may serve as hosts or reservoirs for piroplasms of importance for domestic animals and public health. In the US, some piroplasms (e.g., Babesia spp. and Theileira cervi) have been associated with disease in native and exotic ungulates. Blood from 447 ruminants in Nevada were PCR tested for piroplasms, with 115 individuals from five species or subspecies found positive: 28/46 California bighorn sheep (Ovis canadensis californiana), 1/16 desert bighorn sheep (Ovis canadensis nelson), 70/255 mule deer (Odocoileus hemionus), 14/53 elk (Cervis canadensis nelsoni), and 2/55 pronghorn (Antilocapra americana). Six mountain goats (Oreamnos americanus) and four moose (Alces alces) were negative. Four piroplasm species were detected-Babesia duncani, Babesia sp. RD63, Babesia odocoilei, and Theileria cervi-like spp.-but three B. duncani strains were detected, giving seven unique species or strains. Babesia duncani, the most common piroplasm detected (83%), occurred in California and desert bighorn sheep, elk, and mule deer. Bighorn sheep were only infected with B. duncani, whereas mule deer and elk were each infected with three piroplasm species or strains. The single Theileria sp. and B. odocoilei detections were in pronghorn. Free-ranging ruminants in Nevada are infected with a high diversity of piroplasms, several of which are zoonotic or reported to cause disease in both wild and domestic ruminants., (© Wildlife Disease Association 2024.)

Surveillance of mule deer (Odocoileus hemionus, Rafinesque, 1917) populations for tick-borne diseases has helped define the distribution of these pathogens and their subsequent risk of transmission to humans and domestic animals. We surveyed three mule deer herds across the state of Nevada for infection with relapsing fever Borrelia spp. spirochetes. Bacterial prevalence varied by the county where deer were sampled but Borrelia spirochetes were detected in 7.7% of all deer sampled. Infected deer were identified in every location from which mule deer samples were obtained. Sequencing of the Borrelia intergenic spacer gene (IGS) revealed that one individual was infected with Borrelia coriaceae and all others were infected with Borrelia hermsii. The vector of B. hermsii, Ornithodoros hermsi (Acari: Argasidae, Wheeler, Herms, and Meyer, 1935), feeds primarily on wild rodents and has not been identified infesting deer. Additionally, Ornithodoros coriaceus (Acari: Argasidae, Koch, 1844), which readily feeds on deer and is frequently infected with B. coriaceae, has not been shown to be a competent vector for B. hermsii. Our data represent the first sylvatic evidence of B. hermsii infection in mule deer. Additionally, our data provide evidence that infection with relapsing fever spirochetes in Nevada is wide ranging in the state's deer populations.