Capture and handling of wildlife is essential to answering pertinent questions about ecology and biology. It is important to refine methods to increase animal welfare and safety. Gray wolves (Canis lupus) have been captured annually in Idaho, USA, for management or research purposes since their reintroduction in 1995-96. Two wolves died of hyperthermia during aerial darting in 2015. A retrospective analysis of 490 captures between 1999 and 2018 was conducted to identify factors that might contribute to the likelihood of hyperthermia (body temperature ≥41 C) when using anesthetic drugs in wolves. Wolves were captured in summer (May-October, n=321) by using foothold traps and anesthetized with ketamine-xylazine (n=66), ketamine-medetomidine (n=51), or tiletamine-zolazepam (n=204). Wolves were captured in winter (November-April, n=169) by using aerial darting with ketamine-medetomidine (n=75) or tiletamine-zolazepam (n=94). Mean body temperatures of wolves captured in summer were 39.7 C for ketamine-xylazine, 39.9 C for ketamine-medetomidine, and 39.5 C for tiletamine-zolazepam; in winter, mean temperatures were 40.4 C for ketamine-medetomidine and 39.1 C for tiletamine-zolazepam. In summer captures, hyperthermia occurred in 6/66 (9.1%) of wolves by using ketamine-xylazine, 7/51 (13.7%) by using ketamine-medetomidine, and 19/204 (9.3%) by using tiletamine-zolazepam. For winter captures, hyperthermia occurred in 20/75 (26.7%) of wolves by using ketamine-medetomidine and 7/94 (7.5%) by using tiletamine-zolazepam. Mixed-effects linear regression analysis was used to investigate the role of drug administration on initial body temperature while controlling for demographic and environmental factors. The top models supported effects of drugs administered on initial body temperature for wolves captured in both summer and winter. Ketamine, especially when combined with medetomidine, was associated with greater increased body temperatures than tiletamine-zolazepam, irrespective of season or method of capture.

A novel hoof disease of elk (Cervus elaphus) was described in southwestern Washington, US, in 2008 and was subsequently diagnosed in an adjacent area in northwestern Oregon in 2014. The disease, currently referred to as treponeme-associated hoof disease (TAHD), is characterized by lesions ranging from mild erosions, to severe ulcers with underrunning of the hoof capsule and heel-sole junction, to overgrown and avulsed hoof capsules. Histologically, lesions exhibit epithelial erosion or ulceration, suppurative inflammation, and the presence of argyrophilic spirochetes. We used data collected by the Washington Department of Fish and Wildlife and Oregon Department of Fish and Wildlife from 2008 to 2017 as reference for disease distribution. We then conducted enhanced surveillance in 2018-20 by obtaining 164 submissions from four US Pacific West states. We detected TAHD for the first time in Idaho and northern California, as well as in multiple counties in Washington and Oregon where it had not been previously reported. Given the unexpectedly broad disease distribution, continued surveillance is warranted to determine the full geographic extent of TAHD. From samples of 22 elk, we investigated 16S rRNA gene amplicon sequencing as a technique that could be used to supplement TAHD surveillance. Operational taxonomic units of the family Spirochaetaceae were identified in 10 of 12 histologically diagnosed TAHD-positive cases and two of 10 TAHD-negative cases. Phyla Spirochaetae (P<0.008), Fusobacteria (P<0.006), and Tenericutes (P<0.01) were overrepresented in samples from TAHD-positive feet when compared with TAHD-negative elk. A unique spirochete, PT19, was detected in hooves of 11 elk and from at least one elk in each state. Results support the use of 16S rRNA gene amplicon sequencing as a reliable and informative tool to supplement investigations into distribution and etiology of this presumed polybacterial disease.

Psoroptes are a non-burrowing, ectoparasitic, mange-causing mite that has been documented in American bighorn sheep populations throughout the 19th and 20th centuries; however, it was not seen on Canadian bighorn sheep until 2006. The aim of this study was to determine the potential source of the Psoroptes outbreak in Canadian bighorn sheep. Morphological and molecular analyses were used to compare mites recovered from outbreak-associated bighorn sheep, pet rabbits in Canada, and on historically infested bighorn sheep in the USA. The results revealed that Psoroptes acquired from the Canadian and outbreak-associated American bighorn sheep were morphologically more similar to those collected from rabbits than mites on historically infested bighorn sheep. Outer opisthosomal setae lengths measured an average of 81.7 μm (±7.7 μm) in outbreak associated bighorn mites, 88.9 μm (±12.0 μm) in rabbit mites and 151.2 μm (±16.6 μm) in historically infested bighorn mites. The opisthosomal lobe morphology of bighorn mites in the outbreak herds was also more similar to that of rabbit mites, previously described as P. cuniculi, than historically infested bighorn mites, which match previous descriptions of P. ovis. This finding was supported by DNA sequence data of the mitochondrial cytochrome B gene. This is the first report of Psoroptes of the rabbit ecotype on bighorn sheep. The morphological and molecular data therefore support the hypothesis that the source of Psoroptes outbreak in Canadian bighorn sheep represented a disease spillover event from rabbits rather than transmission from infested American bighorn sheep populations.

Domestic goats are raised for meat, milk and hair production, in herds for rangeland weed control, and as pack animals. Domestic sheep, goats and wild bighorn sheep are all susceptible to a multifactorial pneumonia. We sampled 43 herd goats from 7 herds and 48 pack goats from 11 herds for viral and bacterial serology, parasitology, and Pasteurellaceae microbiology. The goats in this study were in generally good health, although most goats did harbor various pathogens and parasites including several bacteria, specifically Pasteurellaceae, which have been associated with pneumonia in free-ranging bighorn sheep. It is not known if domestic goats can transmit the Pasteurellaceae or other pathogens found in this study readily to wild bighorn sheep. However, due the possibility of transmission, domestic goats in areas in or near bighorn sheep habitat should be managed to minimize the risk of spreading disease agents to bighorn sheep.

ABSTRACT Reliable diagnostic tests are essential for disease investigation and management. This is particularly true for diseases of free‐ranging wildlife where sampling is logistically difficult precluding retesting. Clinical assays for wildlife diseases frequently vary among laboratories because of lack of appropriate standardized commercial kits. Results of diagnostic testing may also be called into question when investigators report different etiologies for disease outbreaks, despite similar clinical and pathologic findings. To evaluate reliability of diagnostic testing for respiratory pathogens of bighorn sheep ( Ovis canadensis ), we conducted a series of ring tests across 6 laboratories routinely involved in detection of Mycoplasma ovipneumoniae , Pasteurellaceae, lktA (the Pasteurellaceae gene encoding leukotoxin), and 3 reference laboratories. Consistency of results for replicate samples within laboratories was high (median agreement = 1.0). Agreement between laboratories was high for polymerase chain reaction (PCR) detection of M. ovipneumoniae and culture isolation of Mannheimia spp. and Bibersteinia trehalosi (median agreement = 0.89–0.95, Kappa = 0.65–0.74), and lower for PCR detection of Mannheimia spp. lktA (median agreement = 0.58, Kappa = 0.12). Most errors on defined status samples were false negatives, suggesting test sensitivity was a greater problem than specificity. However, tests for M. haemolytica and lktA yielded some false positive results. Despite differences in testing protocols, median agreement among laboratories and correct classification of controls for most agents was ≥0.80, meeting or exceeding the standard required by federal proficiency testing programs. This information is valuable for interpreting test results, laboratory quality assessments, and advancing diagnosis of respiratory disease in wild sheep. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

A novel highly pathogenic avian influenza virus belonging to the H5 clade 2.3.4.4 variant viruses was detected in North America in late 2014. Motivated by the identification of these viruses in domestic poultry in Canada, an intensive study was initiated to conduct highly pathogenic avian influenza surveillance in wild birds in the Pacific Flyway of the United States. A total of 4,729 hunter-harvested wild birds were sampled and highly pathogenic avian influenza virus was detected in 1.3% (n = 63). Three H5 clade 2.3.4.4 subtypes were isolated from wild birds, H5N2, H5N8, and H5N1, representing the wholly Eurasian lineage H5N8 and two novel reassortant viruses. Testing of 150 additional wild birds during avian morbidity and mortality investigations in Washington yielded 10 (6.7%) additional highly pathogenic avian influenza isolates (H5N8 = 3 and H5N2 = 7). The geographically widespread detection of these viruses in apparently healthy wild waterfowl suggest that the H5 clade 2.3.4.4 variant viruses may behave similarly in this taxonomic group whereby many waterfowl species are susceptible to infection but do not demonstrate obvious clinical disease. Despite these findings in wild waterfowl, mortality has been documented for some wild bird species and losses in US domestic poultry during the first half of 2015 were unprecedented.

Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (∼3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations.

ABSTRACT Eighteen bighorn sheep ( Ovis canadensis ) with known or suspected contact with domestic ruminants on public or private land were removed to prevent possible disease transmission. Live bighorns maintained in captivity were monitored for evidence of respiratory disease. Contacts with cattle ( n = 4) occurred in December, January, and July; whereas, most contacts with domestic sheep ( n = 10), goats ( n = 3), or both ( n = 1) occurred between April and October. Four bighorns died within 7 days following capture and 10 survived from 47 days to 57 months in captivity. Five bighorns had gross and/or histological evidence of pneumonia. Pasteurellaceae were isolated from 17/18 bighorns, and domestic ruminants that were contacted by 4 bighorns. Isolates included multiple biovariants of Mannheimia spp. and Bibersteinia trehalosi , and Pasteurella multocida subspecies and biotypes. Pasteurellaceae from pneumonic lungs included Mannheimia spp. biovariant 1, P. multocida subsp. multocida a, and B. trehalosi biovariant 2 B . The Mannheimia spp. biovariant 1, isolated from 2 pneumonic bighorns and contacted domestic sheep, had restriction fragment‐length pattern similarity coefficient values of 1.0, indicating high similarity and likely sharing between the species. Management implications include the need for species separation and rapid responses to contact situations because 28% of the bighorns died with evidence of respiratory disease following domestic ruminant contact. © 2014 The Wildlife Society.

Mycoplasma species are of interest as possible primary pathogens in the pneumonia complex of bighorn sheep (Ovis canadensis). Previous investigations have not commonly detected low frequencies of Mycoplasma spp. from free-ranging bighorn sheep, possibly due to the fastidious and slow growth of these organisms. We developed a culture protocol that employed an average initial 3-day enrichment culture in liquid Hayflick broth in a CO(2)-enhanced atmosphere. The broth was plated to solid Hayflick medium and the cultures observed for growth for up to 30 days. Polymerase chain reaction (PCR) was performed on DNA isolated from the enrichment broth and on isolates obtained from culture using Mycoplasma genus-specific PCR assays and species-specific PCR assays for M. arginini and M. ovipneumoniae. Some cultures that grew on Hayflick plates were picked as single colonies but were mixed because two organisms may grow together and appear as a single colony. Culture and PCR tests produced similar results for M. arginini, but for M. ovipneumoniae, culture alone was less accurate than PCR. Use of genus-specific primers also may allow detection of other species in samples negative for M. arginini and M. ovipneumoniae. Two methods of transport from field to laboratory (Port-a-Cul™ tubes, cryoprotectant in liquid N(2) and Fisher Transport System) gave similar results under our study conditions.

OBJECTIVE:To elucidate the species and biovariants of Pasteurellaceae isolated from clinically normal bighorn sheep (Ovis canadensis) or bighorn sheep with evidence of respiratory disease.SAMPLE:675 Pasteurellaceae isolates from 290 free-ranging bighorn sheep in Idaho, Oregon and Wyoming.PROCEDURES:Nasal and oropharyngeal swab specimens were inoculated onto selective and nonselective blood agar media. Representatives of each colony type were classified via a biovariant scheme. The association of respective β-hemolytic isolates with respiratory disease was evaluated via χ(2) analyses.RESULTS:Bacterial isolates belonged to 4 species: Histophilus somni, Mannheimia haemolytica, Pasteurella multocida, and Bibersteinia (Pasteurella) trehalosi. Within the latter 3 species, 112 subspecies, biotypes, and biovariants were identified. Bibersteinia trehalosi 2 and B trehalosi 2B constituted 345 of 675 (51%) isolates. Most (597/618 [97%]) isolates from adult sheep were from clinically normal animals, whereas most (47/57 [82%]) isolates from lambs were from animals with evidence of respiratory disease. Twenty-two Pasteurellaceae biovariants were isolated from sheep with respiratory disease; 17 of these biovariants were also isolated from clinically normal sheep. The ability of isolates to cause β-hemolysis on blood agar was associated with respiratory disease in adult bighorn sheep (OR, 2.59; 95% confidence interval, 1.10 to 6.07).CONCLUSIONS AND CLINICAL RELEVANCE:Bighorn lambs appeared more susceptible to respiratory disease caused by Pasteurellaceae than did adult sheep. β-Hemolytic Pasteurellaceae isolates were more likely to be associated with respiratory disease than were non-β-hemolytic isolates in adult sheep. Identification of Pasteurellaceae with the greatest pathogenic potential will require studies to estimate the risk of disease from specific biovariants.

A retrospective study of Pasteurellaceae isolated from domestic sheep (Ovis aries) was conducted. The aim was to identify Pasteurellaceae present in animals that were clinically healthy and others with evidence of respiratory disease. The bacteria had been isolated from samples submitted to the University of Idaho Caine Veterinary Teaching Center as part of disease diagnostic testing. The 844 isolates identified mainly three species of Pasteurellaceae: Mannheimia haemolytica, Pasteurella multocida, and Pasteurella (Bibersteinia) trehalosi. A total of 114 biovariants were identified among these three species. Individual biovariants were identified 1–180 times. Two of those (M. haemolytica 1 and P. (B.) trehalosi 2) constituted 36% of the isolates, and were the only biovariants sufficiently numerous to account for >7% of the total isolates. Samples were primarily submitted from sheep with signs of respiratory disease. Eighty percent of biovariants were identified most often in animals with signs of respiratory disease, but 26% of biovariants were isolated from both sheep with respiratory disease and apparently healthy sheep. P. multocida constituted 4.7% of isolates, and were exclusively associated with animals with respiratory disease. The ability of isolates to produce beta-hemolysis on culture media was not associated with animals with respiratory disease (odds ratio 0.77, 95% CI 0.50–1.19). The inference of this study is limited due to the retrospective study design. However, it is the first study that provides an extensive baseline list of biovariants associated with respiratory disease in domestic sheep.

This experimental study was conducted to evaluate the susceptibility of American bison (Bison bison) to liver flukes, Fascioloides magna and Fasciola hepatica. Six bison were each experimentally inoculated with 600 metacercariae of Fascioloides magna, and three were later treated with triclabendazole suspension at 40 mg/kg of body weight. Four additional bison were each experimentally inoculated with 600 metacercariae of Fasciola hepatica. Five control bison were placebo controls. Two controls and all inoculated bison were euthanized 10 mo (Fascioloides magna) and 7 mo (Fasciola hepatica) after inoculation. None of the control bison or the bison inoculated with Fascioloides magna had flukes or lesions characteristic of fluke infection at necropsy. All four bison inoculated with Fasciola hepatica had characteristic liver fluke lesions at necropsy, and three of four bison contained four, 103, and adult flukes, respectively. Fluke eggs were detected in feces of all Fasciola hepatica-inoculated bison during the experiment, but not from the Fascioloides magna-infected bison or control bison. Clinical signs of infection were not observed during the experiment, but hemoglobin and packed cell volumes were lower in the Fasciola hepatica bison when compared to controls, and eosinophil levels were increased. Triclabendazole at 40 mg/kg of body weight appeared to be safe in bison because no toxic reactions were observed. Results From this study indicated bison are susceptible to infection with Fasciola hepatica and are efficient definitive hosts. Because no Fascioloides magna were recovered, bison may have a decreased susceptibility or innate resistance to Fascioloides magna infection, which may account for a lack of reported infections in this host.

We evaluated the small intestines of 123 gray wolves (Canis lupus) that were collected from Idaho, USA (n=63), and Montana, USA (n=60), between 2006 and 2008 for the tapeworm Echinococcus granulosus. The tapeworm was detected in 39 of 63 wolves (62%) in Idaho, USA, and 38 of 60 wolves (63%) in Montana, USA. The detection of thousands of tapeworms per wolf was a common finding. In Idaho, USA, hydatid cysts, the intermediate form of E. granulosus, were detected in elk (Cervus elaphus), mule deer (Odocoileus hemionus), and a mountain goat (Oreamnos americanus). In Montana, USA, hydatid cysts were detected in elk. To our knowledge, this is the first report of adult E. granulosus in Idaho, USA, or Montana, USA. It is unknown whether the parasite was introduced into Idaho, USA, and southwestern Montana, USA, with the importation of wolves from Alberta, Canada, or British Columbia, Canada, into Yellowstone National Park, Wyoming, USA, and central Idaho, USA, in 1995 and 1996, or whether the parasite has always been present in other carnivore hosts, and wolves became a new definitive host. Based on our results, the parasite is now well established in wolves in these states and is documented in elk, mule deer, and a mountain goat as intermediate hosts.

Morbidity and mortality associated with respiratory disease following capture and translocation of bighorn sheep (Ovis canadensis canadensis) is a significant concern, particularly when establishing new or augmenting existing bighorn populations. Administration of prophylactic antibiotics at the time of capture is often done to minimize the risk of respiratory disease, but the efficacy of this practice is unknown. The effects of oxytetracycline and florfenicol on the Pasteurella (Bibersteinia) and Mannheimia spp. isolated from samples collected from the oropharynx at the time of capture and 3 or 42 day later were evaluated in two groups of bighorn sheep. The most evident change in the isolation rates or types of Pasteurella (Bibersteinia) spp., Mannheimia spp., or both was an increase of beta-hemolytic strains isolated from bighorn sheep 3 day following oxytetracycline treatment. Both groups of bighorn sheep carried Pasteurella (Bibersteinia) trehalosi identified as the same biovariants, but they did not share biovariants of Mannheimia spp. No animals had signs of respiratory disease. Isolates representative of all biovariants present in cultures from the two bighorn sheep groups were sensitive to in vitro tests to both oxytetracycline and florfenicol and the majority were also sensitive to seven other antibiotics tested. The administration of neither oxytetracycline nor florfenicol eliminated Pasteurella (Bibersteinia) or Mannheimia from the oropharyngeal mucosa. Resistance to either antibiotic used in these animals was not noted. Although the prophylactic benefits of these drugs in preventing disease are uncertain. therapeutic levels of antibiotics in lung tissue during times of stress may reduce the risk of disease. Representative sampling of the oropharyngeal microflora of bighorn sheep source and recipient populations prior to being intermingled should be considered as one of the tools to minimize exposure of naive populations to potentially pathogenic bacteria.

Bighorn sheep are more susceptible to respiratory infection by Mannheimia haemolytica than are domestic sheep. In response to bacterial challenge, macrophages produce a number of molecules that play key roles in the inflammatory response, including highly reactive nitrogen intermediates such as nitric oxide (NO). Supernatants from monocyte-derived macrophages cultured with M. haemolytica LPS were assayed for nitric oxide activity via measurement of the NO metabolite, nitrite. In response to LPS stimulation, bighorn sheep macrophages secreted significantly higher levels of NO compared to levels for non-stimulated macrophages. In contrast, levels of NO produced by domestic sheep macrophages in response to M. haemolytica LPS did not differ from levels detected in non-stimulated cell cultures. Nitrite levels detected in supernatants of LPS-stimulated bighorn macrophage cultures treated with an inducible nitric oxide synthase (INOS) inhibitor, N(G)-monomethyl-L-arginine, were similar to that observed in non-stimulated cultures indicating a role for the iNOS pathway.

Brucellosis occurs in free-ranging elk (Cervus elaphus) and bison (Bison bison) in the Greater Yellowstone Area, which includes portions of Idaho, Wyoming, and Montana. Brucella abortus was first detected in elk in Idaho in 1998, and from 1998 to 2002, serologic surveillance of hunter-killed elk was conducted in northeastern and southeastern Idaho. Prevalence of antibodies in these elk varied annually, but averaged between 2% and 3%. Elk were also trapped in northeastern Idaho from 1998-2002 and tested for brucellosis using serology and tissue culture. In areas where artificial feeding of elk was done, antibody prevalence ranged from 12% to 80% depending on site, age, and sex. At one feeding site (Rainey Creek), a decline in the prevalence of antibodies (from 56.8% in 1999 to 13.5% in 2002) was detected after the removal of seropositive elk over 4 yr. Seropositive elk removed from two artificial winter feeding sites (Rainey Creek and Conant Creek) were euthanized and sampled or held in captivity and allowed to calve prior to euthanasia and necropsy. At necropsy, B. abortus biovar 1 and B. abortus biovar 4 were isolated from both cows and calves; however, biovar 4 was predominant. A dual infection with both biovars was found in one calf born to a seropositive cow from which biovar 4 was isolated. Abortions (16%), stillbirths (8%), and weak calves (4%) were observed in these elk. These findings confirm the presence of brucellosis in elk in eastern Idaho and provide information on disease management options.

Dr. Wilbur B. Amand, PA; Mr. John R. Behrmann, PA; Mr. Alan G. Clark, UT; Dr. Wayne E. Cunningham, CO; Dr. John C. Doyle, OK; Dr. Mark L. Drew, ID; Dr. John R. Fischer, GA; Dr. Michael J. Gilsdorf, MD; Dr. Chester A. Gipson, MD; Dr. Sam D. Holland, SD; Dr. David L. Hunter, MT; Dr. Dave Jessup, CA; Dr. Patrice N. Klein, MD; Dr. Jim Logan, WY; Dr. Calvin W. S. Lum, HI; Mr. Daniel P. Marsh, MI; Dr. Thomas P. Meehan, IL; Mrs. Phyllis Menden, WI; Dr. Lyle D. Miller, IL; Dr. Janet B. Payeur, IA; Mr. Shawn P. Schafer, ND; Mr. Tom A. Scheib, WI; Dr. David D. Schmitt, IA; Dr. Dale F. Schwindaman, MD; Mr. Charly Seale, TX; Mr. J. Gary Shoun, CO; Dr. Joe Starcher, WV; Dr. Pamela K. Swift, CA; Dr. Scott R. Syska, MO; Dr. Robert M. S. Temple, OH; Dr. Charles O. Thoen, IA; Dr. John B. Thurston, IN; Dr. Samuel J. Vainisi, WI; Dr. Kenneth Waldrup, TX; Mr. Dave Whittlesey, CO; Mr. Richard W. Winters, Jr., TX; Mr. Steve Wolcott, CO; Ms. Jill Bryar Wood, TX; Dr. Glen L. Zebarth, MN.