Bighorn Sheep (Ovis canadensis) with Higher Whole Blood Selenium Levels Have Improved Survival and Altered Immune Responses.

Bighorn sheep (Ovis canadensis) are herbivorous ungulates that live in forage-poor areas of the American west. The trace minerals that herbivores derive from forage are important for immune function. Therefore, identifying trace minerals that affect immune function in bighorn sheep could provide important insights into disease susceptibility and population health in threatened populations. We sought to determine whether trace mineral composition in blood or plasma correlates to survival and determine whether immunologic parameters correlate with any trace minerals that affect survival. We used data collected from 2016 to 2018 as part of a large study on bighorn sheep in southeastern Oregon and northern Nevada, US. We measured the survival of 135 bighorn sheep during the 8-mo monitoring period, including general metrics of immune function and trace mineral levels. We found that animals with higher selenium had improved survival over the monitoring period, with higher peripheral blood mononuclear cell activity (lymphocytes and monocytes) and lower bacterial killing ability in an in vitro assay. This suggests that bighorn sheep may have altered immune function when selenium levels are low, making them more likely to die during the 8-mo monitoring period. Future work should consider whether habitat management strategies that increase selenium intake might improve disease resistance and survival in bighorn sheep in selenium-poor areas.

A MIXTURE OF NALBUPHINE, AZAPERONE, AND MEDETOMIDINE FOR IMMOBILIZING RINGTAILS (BASSARISCUS ASTUTUS).

We evaluated a combination of nalbuphine HCl (40 mg/mL), azaperone tartrate (10 mg/mL), and medetomidine HCl (10 mg/mL), a combination known as NAM or NalMed-A, in 23 ringtails (Bassariscus astutus) during 29 handling events for a radio-collaring study in southern Oregon, US, from August 2020 to March 2022. The combination was delivered to ringtails by hand injection at 0.075 mL NAM per estimated 1 kg body mass. The mean (± standard deviation, SD) dosage calculated post hoc was 3.366 (±0.724) mg/kg nalbuphine, 0.841 (±0.181) mg/kg medetomidine, and 0.841 (±0.181) mg/kg azaperone. All captured ringtails were effectively immobilized with a mean (SD) induction time of 13.24 (±3.57) min. The medetomidine and nalbuphine components were antagonized with a combination of atipamezole and naltrexone HCl with a mean (SD) recovery time of 2.48 (±1.94) min. This combination appeared to be safe and effective for immobilizing ringtails with a low volume dose, smooth antagonism, and rapid recovery. In addition, NAM does not contain any drugs that are US Drug Enforcement scheduled, which makes it useful for immobilization procedures by wildlife professionals in the US.

Associations between urogenital carcinoma and DECA-BDE (BDE-209) among wild California Sea lions (Zalophus californianus) and Steller Sea lions (Eumetopias jubatus).

Urogenital carcinoma (UGC) is prevalent among California sea lions (Zalophus californianus), while less is known concerning UGC among Steller sea lions (Eumetopias jubatus). Our objective was to investigate associations between UGC and polybrominated diphenyl ethers (PBDEs) among both sea lion species. Twenty-nine California sea lions and 20 Steller sea lions were lethally removed from the Columbia River Basin, Oregon, USA between 2020 and 2021, under Section 120 of the Marine Mammal Protection Act. UGC was diagnosed through gross necropsy and histopathology. Forty PBDE congeners were analyzed in blubber, including BDE-209, a potential carcinogen. Twenty (69 %) California sea lions and one (5 %) Steller sea lion were diagnosed with UGC. All cases were identified as early stage UGC, aside from one California sea lion with more advanced stage UGC. Among California sea lions, associations between PBDEs and UGC were analyzed using logistic regression. In the adjusted model, BDE-209 (log2-transformed) was associated with increased odds of UGC [Odds Ratio (OR): 4.68, 95 % confidence interval: 1.04, 21.0, OR p-value = 0.044). This is the first study to report BDE-209 concentrations in sea lion blubber. The percentages of California and Steller sea lions diagnosed with UGC were higher than expected for wild (non-stranded) sea lions. Our results suggested blubber BDE-209 was potentially associated with UGC in California sea lions in the Columbia River Basin.

SURVEILLANCE FOR AN EMERGENT HOOF DISEASE IN ELK (CERVUS ELAPHUS) IN THE US PACIFIC WEST SUPPLEMENTED BY 16S RRNA GENE AMPLICON SEQUENCING.

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.

Molecular identification of clinical and environmental avian Aspergillus isolates.

Aspergillosis causes high morbidity and mortality in avian species. The main goal of this study was to use molecular techniques to identify Aspergillus species collected from different avian species with aspergillosis. A subsample of those isolates was also screened for resistance to itraconazole. Over a 2-year period, clinical samples were recovered from 44 birds with clinical signs of the disease, clinical pathology results suspicious of aspergillosis, or from birds that died from Aspergillus spp. infection. Environmental sampling was also performed in seabird rehabilitation centers and natural seabird environments. Seventy-seven isolates (43 clinical and 34 environmental) were identified as Aspergillus fumigatus sensu stricto. No cryptic species from the Fumigati section were detected. Two environmental isolates were identified as Aspergillus nidulans var. dentatus and Aspergillus spinulosporus. None of the Aspergillus isolates tested were resistant to itraconazole. Our study emphasizes the dominant association of Aspergillus fumigatus sensu stricto in avian mycoses and shows the lack of itraconazole resistance in the studied isolates.

Monitoring of fungal loads in seabird rehabilitation centers with comparisons to natural seabird environments in northern California.

Aspergillosis remains a major cause of mortality in captive and rehabilitated seabirds. To date, there has been poor documentation of fungal (particularly Aspergillus spp.) burdens in natural seabird loafing and roosting sites compared with fungal numbers in rehabilitation or captive settings and the various microenvironments that seabirds are exposed to during the rehabilitation process. This study compares fungal, particularly Aspergillus spp., burdens potentially encountered by seabirds in natural and rehabilitation environments. Differences among the various microenvironments in the rehabilitation facility were evaluated to determine the risk of infection when seabirds are experiencing high stress and poor immune function. Aspergillus spp. counts were quantified in three wildlife rehabilitation centers and five natural seabird loafing and roosting sites in northern California using a handheld impact air sampler and a water filtration system. Wildlife rehabilitation centers demonstrated an increase in numbers of conidia of Aspergillus spp. and Aspergillus fumigatus in air and water samples from select aquatic bird rehabilitation centers compared with natural seabird environments in northern California. Various microenvironments in the rehabilitation facility were identified as having higher numbers of conidia of Aspergillus spp. These results suggest that periodic monitoring of multiple local areas, where the birds spend time in a rehabilitation facility, should be done to identify "high risk" sites, where birds should spend minimal time, or sites that should be cleaned more frequently or have improved air flow to reduce exposure to fungal conidia. Overall, these results suggest that seabirds may be more likely to encounter Aspergillus spp. in various microenvironments in captivity, compared with their native habitats, which could increase their risk of developing disease when in a debilitated state.

Evaluation of plasma (1-->3) beta-D-glucan concentrations in birds naturally and experimentally infected with aspergillus fumigatus.

Avian aspergillosis, most often caused by Aspergillus fumigatus, is a common and devastating disease affecting a range of bird species. Early diagnosis is difficult and often unreliable. The current study evaluated the utility of measuring (1-->3)-beta-D-glucan (BG) concentrations in avian plasma samples to aid in the diagnosis of aspergillosis. We evaluated a commercially available BG assay (Fungitell, Beacon Diagnostics) using 178 plasma samples from naturally infected, experimentally infected, and aspergillosis-free birds. Although there was variation in BG concentration, as reflected by high standard deviations, seabirds with confirmed aspergillosis had the highest mean BG concentrations (M = 3098.7 pg/dl, SD = 5022.6, n = 22) followed by companion avian species and raptors with confirmed aspergillosis (M = 1033.8 pg/dl, SD = 1531.6, n = 19) and experimentally infected Japanese quail (Coturnix japonica; M = 1066.5 pg/dl, SD = 1348.2, n = 17). Variation in severity of disease, differences among species of birds with and without disease, and also different levels in environmental exposure likely contribute to the differences among avian groups. The overall sensitivity and specificity of the BG test for diagnosis of aspergillosis in birds was 60.0 and 92.7%, respectively, with an overall optimized avian cut-offvalue of > or = 461 pg/dl for positive disease. Our findings suggest that, although BG concentrations are highly variable between and within different avian groups, it could serve as a useful adjunctive diagnostic test for aspergillosis that is applicable to multiple avian species in some settings, particularly as a negative predictor of infection.

Acute lead toxicosis via ingestion of spent ammunition in a free-ranging cougar (Puma concolor).

Lead toxicity has long been documented and acknowledged as a significant health issue of water birds and avian scavengers. However, few instances of toxic effects to higher mammalian carnivores have been documented. Here we present an acute case of lead toxicity in a free-ranging cougar (Puma concolor) in Oregon.

Molecular sub-typing suggests that the environment of rehabilitation centers may be a potential source of Aspergillus fumigatus infecting rehabilitating seabirds.

Aspergillosis remains a major cause of infection-related avian mortality in birds that are debilitated and undergoing rehabilitation for release into the wild. This study was designed to understand the source of avian aspergillosis in seabirds undergoing rehabilitation at selected northern California aquatic bird rehabilitation centers. Air, surface and water sampling was performed between August 2007 and July 2008 in three such centers and selected natural seabird loafing sites. Average air Aspergillus fumigatus counts were at least nine times higher in samples obtained from the rehabilitation sites (M = 7.34, SD = 9.78 CFU/m(3)), when compared to those found at natural sites (M = 0.76, SD = 2.24 CFU/m(3)), t (205) = -5.99, P < 0.001. A total of 37 A. fumigatus isolates from birds with confirmed aspergillosis and 42 isolates from environmental samples were identified using both morphological and molecular methods, and subsequently sub-typed using an eight-locus microsatellite panel with the neighbor joining algorithm. Results of the study demonstrated the presence of five clonal groups, 13 genotypically related clusters, and 59 distinct genotypes. Six of the 13 genotypically related clusters contained matching genotypes between clinical isolates and local environmental isolates from the rehabilitation center in which these birds were housed. We present evidence that the environment of rehabilitation centers may be a source for A. fumigatus infection in rehabilitated seabirds.