Adenovirus hemorrhagic disease affects primarily mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus), Rocky Mountain elk (Cervus canadensis nelsoni), and moose (Alces alces) in their first year of life. The method by which the causative virus, Deer atadenovirus A, is maintained in the environment and transmitted to neonates is unknown. In this study, we investigated the potential transmission of the virus from dam to offspring in Rocky Mountain mule deer (Odocoileus hemionus hemionus) and elk in western Wyoming, US. We sampled dams before parturition during placement of vaginal implant transmitters and at parturition and sampled neonates during capture in their first days of life. We also tested for the virus in mortalities submitted for pathologic examination and laboratory analysis. We detected viral DNA in samples from all time points tested but did not find a connection between positive dams and offspring mortalities associated with adenovirus hemorrhagic disease. Although we did not find direct evidence of transmission events between dams and offspring, asymptomatic animals shedding of Deer atadenovirus A, are a likely source of infection in neonates.

Mycoplasma bovis is 1 of several bacterial pathogens associated with pneumonia in cattle. Its role in pneumonia of free-ranging ungulates has not been established. Over a 3-month period in early 2019, »60 free-ranging pronghorn with signs of respiratory disease died in northeast Wyoming, USA. A consistent finding in submitted carcasses was severe fibrinosuppurative pleuropneumonia and detection of M. bovis by PCR and immunohistochemical analysis. Multilocus sequence typing of isolates from 4 animals revealed that all have a deletion in 1 of the target genes, adh-1. A retrospective survey by PCR and immunohistochemical analysis of paraffin-embedded lung from 20 pronghorn that died with and without pneumonia during 2007–2018 yielded negative results. These findings indicate that a distinct strain of M. bovis was associated with fatal pneumonia in this group of pronghorn.

Brucella ovis causes a sexually transmitted, infectious disease of domestic sheep characterized by genital lesions and epididymitis in rams, placentitis and rare abortions in ewes, and neonatal mortality in lambs. This study was designed to 1) estimate animal and flock seroprevalence of B. ovis in sheep across Wyoming, USA, and 2) describe epidemiologic risk factors associated with seropositive sheep and flocks. For the animal seroprevalence estimate, 2423 blood samples were collected from sheep on 18 producer-selected operations and a questionnaire about possible risk factors was distributed. For the flock seroprevalence estimate, blood samples from 82 operations were obtained, including samples from the previous 18 operations and 64 additional operations that sent samples to the Wyoming State Veterinary Laboratory for diagnostic testing. Categorical risk factors were created based on questionnaires and submission forms. Sera was analyzed using the B. ovis enzyme-linked immunosorbent assay. Estimated true animal and flock seroprevalence were 0.53% (95% CI: 0.21–1.01%; 22/2,423) and 22.5% (95% CI: 14–32%; 18/82), respectively. Using Fisher’s exact and Mid-p exact tests to compare apparent seroprevalence with respect to possible risk factors, increased age and breed type were risk factors associated with seropositive sheep, while region and large flock size were risk factors associated with seropositive flocks. Results from this study suggest few sheep have been exposed to B. ovis, but many flocks contain at least one seropositive animal. Each region in Wyoming contained at least one seropositive animal and flock, emphasizing the importance of disease-free documentation before purchasing new sheep. Aged sheep (≥ 6 years of age) had the highest seroprevalence among age groups; hence, we propose the separation of young rams from older rams to help reduce disease spread outside the breeding season. Wool breeds (Rambouillet and Merino) may be less susceptible to B. ovis infection given they had the lowest animal seroprevalence of the breed types, and large flocks (> 100 breeding rams) had the highest seroprevalence of the flock size categories, likely due to more intensive management strategies that can contribute to the introduction and persistence of B. ovis infection in sheep and flocks.

Brucella ovis is a bacterial pathogen present in most major sheep-producing regions of the world. The pathogen is associated with ram infertility, decreased ewe conception rates, and premature lambs. Twenty ELISA seropositive or indeterminate rams were culled from a B. ovis-positive flock, and donated to the Wyoming State Veterinary Laboratory for evaluation of infection. Tissues from each ram were collected at autopsy for additional testing, including bacterial culture, PCR, and histopathology. Of 17 seropositive rams, 11 rams were also positive by culture and PCR, and had evidence of mild histologic lesions; 1 seropositive ram was positive by culture with mild histologic lesions, but negative by PCR. Five seropositive rams were negative by culture and PCR and had no histologic lesions. Three indeterminate rams were negative by culture and by PCR and had no histologic lesions. The tissues in which B. ovis was most often detected included the epididymis, vesicular gland, and ampulla. Although this was a small study, the observation that 5 of 17 (29%) rams that were initially seropositive had no evidence of infection is interesting. A convalescent test for valuable seropositive animals prior to culling may be useful, and reproductive tissues may be evaluated postmortem if confirmatory testing is desired.

We present the first complete genome sequence of Odocoileus hemionus deer adenovirus 1 (OdAdV-1). This virus can cause sporadic haemorrhagic disease in cervids, although epizootics with high mortality have occurred in California. OdAdV-1 has been placed in the genus Atadenovirus, based on partial hexon, pVIII and fibre genes. Ten field isolates recovered from naturally infected mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginiana) and moose (Alces alces) from Wyoming, black-tailed deer (Odocoileus hemionus columbianus) from California, and Rocky Mountain elk (Cervus elaphus nelsoni) from Colorado and Washington state were sequenced. The genome lengths ranged from 30 620 to 30 699 bp, contained the predicted proteins and gene organization typical of members of genus Atadenovirus, and had a high percentage of A/T nucleotides (66.7 %). Phylogenic analysis found that the closest ancestry was with ruminant atadenoviruses, while a divergence of the hexon, polymerase and penton base proteins of more than 15 % supports classification as a new species. Genetic global comparison between the 10 isolates found an overall 99 % identity, but greater divergence was found between those recovered from moose and elk as compared to deer, and a single variable region contained most of these differences. Our findings demonstrate that OdAdV-1 is highly conserved between 10 isolates recovered from multiple related cervid species, but genotypic differences, largely localized to a variable region, define two strains. We propose that the virus type name be changed to cervid adenovirus 1, with the species name Cervid atadenovirus A. Sequence data were used to develop molecular assays for improved detection and genotyping.

ABSTRACTChronic wasting disease (CWD) is an infectious and fatal transmissible spongiform encephalopathy of members of the family Cervidae. Although CWD has been a serious concern among wildlife managers in several states in the United States and 2 Canadian provinces for over a decade, it is not known how CWD affects movement of hosts during the preclinical and clinical phases of disease. We hypothesized that normal movement patterns are altered by CWD. We evaluated migratory status, migration corridors, dispersal behavior, hourly activity patterns, home range areas, and resource selection for white‐tailed deer (Odocoileus virginianus) of known CWD status as a means of understanding how CWD infection influenced habitat use and disease spread. We captured deer, tested for CWD by tonsil biopsy, marked deer with radio‐transmitters (2003–2010) or global positioning system collars (2006–2010), and recaptured individuals annually for CWD testing. The proportion of CWD‐positive females that migrated was significantly less than CWD‐positive males. All deer that were CWD‐negative were more active than their CWD‐positive cohabitants, which was most pronounced in fall for males when CWD‐positive deer were significantly less active throughout the day. Home range areas were small ( = 1.99 km2) and were larger for CWD‐negative females than CWD‐positive females. Resource selection analyses indicated that all deer, regardless of CWD status, sex, or migratory status selected riparian habitats. Riparian habitats represent high CWD risk areas that should be targeted for potential disease management actions (e.g., surveillance, culling, environmental treatments). © 2017 The Wildlife Society.

Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting white-tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), Rocky Mountain elk (Cervus elaphus nelsoni), and moose (Alces alces shirasi) in North America. In southeastern Wyoming average annual CWD prevalence in mule deer exceeds 20% and appears to contribute to regional population declines. We determined the effect of CWD on mule deer demography using age-specific, female-only, CWD transition matrix models to estimate the population growth rate (λ). Mule deer were captured from 2010-2014 in southern Converse County Wyoming, USA. Captured adult (≥ 1.5 years old) deer were tested ante-mortem for CWD using tonsil biopsies and monitored using radio telemetry. Mean annual survival rates of CWD-negative and CWD-positive deer were 0.76 and 0.32, respectively. Pregnancy and fawn recruitment were not observed to be influenced by CWD. We estimated λ = 0.79, indicating an annual population decline of 21% under current CWD prevalence levels. A model derived from the demography of only CWD-negative individuals yielded; λ = 1.00, indicating a stable population if CWD were absent. These findings support CWD as a significant contributor to mule deer population decline. Chronic wasting disease is difficult or impossible to eradicate with current tools, given significant environmental contamination, and at present our best recommendation for control of this disease is to minimize spread to new areas and naïve cervid populations.

Chronic wasting disease (CWD) is an invariably fatal transmissible spongiform encephalopathy of white-tailed deer, mule deer, elk, and moose. Despite a 100% fatality rate, areas of high prevalence, and increasingly expanding geographic endemic areas, little is known about the population-level effects of CWD in deer. To investigate these effects, we tested the null hypothesis that high prevalence CWD did not negatively impact white-tailed deer population sustainability. The specific objectives of the study were to monitor CWD-positive and CWD-negative white-tailed deer in a high-prevalence CWD area longitudinally via radio-telemetry and global positioning system (GPS) collars. For the two populations, we determined the following: a) demographic and disease indices, b) annual survival, and c) finite rate of population growth (λ). The CWD prevalence was higher in females (42%) than males (28.8%) and hunter harvest and clinical CWD were the most frequent causes of mortality, with CWD-positive deer over-represented in harvest and total mortalities. Survival was significantly lower for CWD-positive deer and separately by sex; CWD-positive deer were 4.5 times more likely to die annually than CWD-negative deer while bucks were 1.7 times more likely to die than does. Population λ was 0.896 (0.859-0.980), which indicated a 10.4% annual decline. We show that a chronic disease that becomes endemic in wildlife populations has the potential to be population-limiting and the strong population-level effects of CWD suggest affected populations are not sustainable at high disease prevalence under current harvest levels.

Abstract OBJECTIVE To compare the humoral response between sheep vaccinated with a killed-virus (KV) vaccine and those vaccinated with a modified-live virus (MLV) vaccine against bluetongue virus (BTV) serotype 17. DESIGN Randomized clinical trial followed by a field trial. ANIMALS 30 yearling crossbred ewes (phase 1) and 344 sheep from 7 Wyoming farms (phase 2). PROCEDURES In phase 1, ewes seronegative for anti-BTV antibodies received sterile diluent (control group; n = 10) or an MLV (10) or KV (10) vaccine against BTV-17 on day 0. Ewes in the KV group received a second dose of the vaccine on day 21. Ewes were bred 5 months after vaccination and allowed to lamb. Anti-BTV antibodies were measured in ewes at predetermined times after vaccination and in their lambs once at 5 to 10 days after birth. In phase 2, 248 commercial sheep were screened for anti-BTV antibodies and vaccinated with a KV vaccine against BTV-17 on day 0. Sheep seronegative for anti-BTV antibodies on day 0 (n = 90) underwent follow-up serologic testing on day 365 along with 96 unvaccinated cohorts (controls). RESULTS In phase 1, all vaccinated ewes developed anti-BTV antibodies by 14 days after vaccination and remained seropositive for 1 year; all of their lambs were also seropositive. All control ewes and lambs were seronegative. In phase 2, the prevalence of vaccinated sheep with anti-BTV antibodies 1 year after vaccination was 93% and 76% as determined by a serum neutralization assay and competitive ELISA, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Both vaccines induced antibodies against BTV-17 that persisted for at least 1 year and provided passive immunity for lambs and may be a viable option to protect sheep against disease.

Mucosal disease (MD) affected a single-source group of 461 recently purchased yearling steers shortly after vaccination with a multivalent vaccine containing 2 strains of modified-live bovine viral diarrhea virus (BVDV). Terminal disease affected 21 steers at 18 to 66 days post-vaccination, and was confirmed as mucosal disease in 3 carcasses examined postmortem. An additional 17 animals identified as persistently infected remained asymptomatic during the study A laboratory study was undertaken to determine whether mucosal disease was triggered by a BVDV in the multivalent vaccine. Purified cytopathic BVDV isolates from 2 animals that died early in the outbreak were genetically identical (>99%) to the vaccine type 2 BVDV strain 125a in 3 genomic regions: 5′-untranslated region to the Npro, E2, and NS2/3. This genetic identity combined with the presence of a single peak outbreak occurring soon after vaccination suggests that the vaccine BVDV was the cause of mucosal disease in these steers. The investigation underscores laboratory challenges in determining the role of vaccinal BVDV when mucosal disease affects multiple animals within 2 months of vaccination, and the need for laboratory testing to identify all persistently infected animals.

Brucella abortus RB51 is the vaccine strain currently licensed for immunizing cattle against brucellosis in the United States. Most cattle are vaccinated as heifer calves at 4–12 months of age. Adult cattle may be vaccinated in selected high-risk situations. Two herds of pregnant adult cattle in the brucellosis-endemic area of Wyoming were vaccinated with a standard label dose (1.0–3.4 × 1010 organisms) of RB51. Reproductive losses in the vaccinated herds were 5.3% (herd A) and 0.6% (herd B) and included abortions, stillbirths, premature calves, and unbred cows (presumed early abortion). Brucella abortus was cultured from multiple tissues of aborted and premature calves (7/9), and from placenta. Isolates were identified as B. abortus strain RB51 by standard strain typing procedures and a species-specific polymerase chain reaction. Bronchopneumonia with intralesional bacteria and placentitis were observed microscopically. There was no evidence of involvement of other infectious or toxic causes of abortion. Producers, veterinarians, and laboratory staff should be alert to the risk of abortion when pregnant cattle are vaccinated with RB51, to potential human exposure, and to the importance of distinguishing field from vaccinal strains of B. abortus.

Canine distemper is uncommon in the pet trade in the United States, in large part due to effective vaccines against Canine distemper virus (CDV). This is a report of CDV affecting 24 young dogs of multiple breeds shortly after sale by 2 pet stores in Wyoming during August-October 2010. Cases were diagnosed over 37 days. Diagnosis was established by a combination of fluorescent antibody staining, reverse transcription polymerase chain reaction, negative stain electron microscopy, and necropsy with histopathology. Viral hemagglutinin gene sequences were analyzed from 2 affected dogs and were identical (GenBank accession no. JF283477). Sequences were distinct from those in a contemporaneous unrelated case of CDV in a Wyoming dog (JF283476) that had no contact with the pet store dogs. The breeding property from which the puppies originated was quarantined by the Kansas Animal Health Department. Puppies intended for sale were tested for CDV. Canine distemper was diagnosed on site in November 2010. At that point 1,466 dogs were euthanized to eliminate dispersal of the disease through commercial channels. The investigation underscores the risks inherent in large-scale dog breeding when vaccination and biosecurity practices are suboptimal.

Infections of domesticated dogs by a worldwide parasitic nematode Filaroides osleri (Oslerus osleri) lead to verminous tracheobronchitis that are often misdiagnosed clinically as kennel cough, due to infection with the bacterium Bordetella bronchiseptica. Diagnosis of two canine cases in Wyoming, USA prompted a search of the literature of canid infections in North America. Infections of domestic dogs are reported in nine US states and four Canadian provinces. Dogs of multiple breeds and both sexes were infected. Most were two years old or younger at diagnosis. Anthelmintic treatments were effective in relieving clinical symptoms, as well as causing resolution of tracheobronchial nodules. Other canid species, including coyotes (Canis latrans) and wolves (Canis lupus), have been infected across North America with a prevalence of 23% and 4%, respectively. Infection with F. osleri should be included in the differential diagnosis of infectious tracheobronchitis of dogs. It can be confirmed most readily by endoscopic detection of distinctive submucosal parasite-filled nodules, combined with histological examination of endoscopic biopsies.

Objective —To characterize a 2007 bluetongue disease (BT) epizootic caused by bluetongue virus (BTV) serotype 17 in sheep in the Big Horn Basin of Wyoming. Design —Cross-sectional study. Animals —1,359 sheep from ranches in Wyoming and Montana. Procedures —Information on clinical signs and history of BT in sheep was obtained from ranchers and attending veterinarians. At 3 to 6 months after the 2007 BT epizootic, blood samples were collected from rams, ewes, and lambs within and outside the Big Horn Basin; blood samples were also collected from lambs born in the spring of 2008. Sera were tested for anti-BTV antibodies by use of a competitive ELISA to determine the seroprevalence of BTV in sheep and to measure antibody titers. Virus isolation and reverse transcriptase PCR assays were used to determine long-term presence of the infectious virus or viral genetic material in RBCs of sheep. Results —The percentage of sheep seropositive for BTV closely matched morbidity of sheep within flocks, indicating few subclinical infections. Flocks separated by as little as 1 mile had substantial variation in infection rate. Rams were infected at a higher rate than ewes. There was no evidence of BTV successfully overwintering in the area. Conclusions and Clinical Relevance —This epizootic appears to be a new intrusion of BTV into a naïve population of sheep previously protected geographically by the mountains surrounding the Big Horn Basin. Rams may have a higher infection rate as a result of increased vector biting opportunity because of the large surface area of the scrotum.

Surveys for disease agents were conducted in introduced free-ranging elk (Cervus elaphus nelsoni) in Arkansas and Kentucky. Elk had been captured in Colorado and Nebraska and released in Arkansas during 1981–1985. From 1997 through 2002 elk were captured in Arizona, Kansas, North Dakota, New Mexico, Oregon, and Utah and released in southeastern Kentucky. Specimens were collected from 170 hunter-killed elk in Arkansas during 1998–2006, and 44 elk in Kentucky during 2001–2004. Significant findings included isolation of Mycobacterium avium paratuberculosis from one elk in Kentucky and evidence of previous or current infections by Parelaphostrongylus tenuis in several animals in Arkansas. Serological tests provided evidence of previous infection by epizootic hemorrhagic disease virus, bluetongue virus, bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza-3 virus, and multiple serovars of Leptospira interrogans. Mycobacterium bovis, Brucella abortus, chronic wasting disease (CWD), and hemoparasites such as Anaplasma spp. were not detected. Results from elk obtained through these surveys were consistent with exposure to disease agents endemic in livestock and wildlife in Arkansas and Kentucky.

Sporadic outbreaks of vesicular stomatitis (VS) in the United States result in significant economic losses for the U.S. livestock industries because VS is a reportable disease that clinically mimics foot-and-mouth disease. Rapid and accurate differentiation of these 2 diseases is critical because their consequences and control strategies differ radically. The objective of the current study was to field validate a 1-tube multiplexed real-time reverse transcription polymerase chain reaction (real-time RT-PCR) assay for the rapid detection of Vesicular stomatitis New Jersey virus and Vesicular stomatitis Indiana virus strains occurring in Mexico and North and Central America. A comprehensive collection of 622 vesicular lesion samples obtained from cattle, horses, and swine from throughout Mexico and Central America was tested by the real-time RT-PCR assay and virus isolation. Overall, clinical sensitivity and specificity of the real-time RT-PCR were 83% and 99%, respectively. Interestingly, VS virus isolates originating from a specific region of Costa Rica were not detected by real-time RT-PCR. Sequence comparisons of these viruses with the real-time RT-PCR probe and primers showed mismatches in the probe and forward and reverse primer regions. Additional lineage-specific primers and a probe corrected the lack of detection of the missing genetic lineage. Thus, this assay reliably identified existing Mexican and Central American VS viruses and proved readily adaptable as new VS viruses were encountered. An important secondary result of this research was the collection of hundreds of new VS virus isolates that provide a foundation from which many additional studies can arise.

Greater Sage-grouse (Centrocercus urophasianus) are a species of concern due to shrinking populations associated with habitat fragmentation and loss. Baseline health parameters for this species are limited or lacking, especially with regard to tissue metal concentrations. To obtain a range of tissue metal concentrations, livers were collected from 71 Greater Sage-grouse from Wyoming and Montana. Mean +/- SE metal concentrations (mg/kg wet weight) in liver were determined for vanadium (V) (0.12 +/- 0.01), chromium (Cr) (0.50 +/- 0.02), manganese (Mn) (2.68 +/- 0.11), iron (Fe) (1,019 +/- 103), nickel (Ni) (0.40 +/- 0.04), cobalt (Co) (0.08 +/- 0.02), copper (Cu) (6.43 +/- 0.40), mercury (Hg) (0.30 +/- 0.09), selenium (Se) (1.45 +/- 0.64), zinc (Zn) (59.2 +/- 4.70), molybdenum (Mo) (0.93 +/- 0.07), cadmium (Cd) (1.44 +/- 0.14), barium (Ba) (0.20 +/- 0.03), and lead (Pb) (0.17 +/- 0.03). In addition to providing baseline data, metal concentrations were compared between sex, age (juvenile/adult), and West Nile virus (WNv) groups (positive/negative). Adult birds had higher concentrations of Ni and Cd compared to juveniles. In addition, Zn and Cu concentrations were significantly elevated in WNv-positive birds.