Adenoviral hemorrhagic disease in a farmed elk (Cervus canadensis) in Alberta, Canada.

Adenoviral hemorrhagic disease (AHD), caused by deer atadenovirus A (OdAdV-1), affects captive and free-ranging cervids across North America. Here we present a case of AHD in a 6-month-old female elk calf from a farm in Alberta. Histopathology revealed multisystemic vasculitis with endothelial intranuclear inclusion bodies, pulmonary hemorrhage, and small intestinal hemorrhage characteristic of the acute systemic form of AHD. Immunohistochemistry was positive for OdAdV-1, confirming the diagnosis. Whole-genome sequencing of the virus was conducted for phylogenetic comparison. This is the 1st reported case of AHD in a farmed elk in Canada and the 1st reported case in an elk in Alberta. Key clinical message: Adenoviral hemorrhagic disease (AHD) is an emerging disease that should be investigated as a top differential when diagnosticians and veterinarians encounter young cervids found dead with pulmonary edema or hemorrhage and/or hemorrhagic enteropathy.

Maladie hémorragique adénovirale chez un wapiti d'élevage (Cervus canadensis) en Alberta, Canada. La maladie hémorragique adénovirale (AHD), causée par l'atadénovirus A du cerf (OdAdV-1), affecte les cervidés en captivité et en liberté partout en Amérique du Nord. Nous présentons ici un cas d'AHD chez un wapiti femelle de 6 mois d'une ferme en Alberta. L'histopathologie a révélé une vascularite multi-systémique avec des corps d'inclusion intranucléaires endothéliaux, une hémorragie pulmonaire et une hémorragie de l'intestin grêle caractéristiques de la forme systémique aiguë de l'AHD. L'immunohistochimie était positive pour OdAdV-1, confirmant le diagnostic. Le séquençage du génome entier du virus a été réalisé à des fins de comparaison phylogénétique. Il s'agit du premier cas signalé d'AHD chez un wapiti d'élevage au Canada et du premier cas signalé chez un wapiti en Alberta.Message clinique clé :La maladie hémorragique adénovirale (AHD) est une maladie émergente qui devrait être investiguée comme un diagnostic différentiel important lorsque les diagnosticiens et les vétérinaires rencontrent de jeunes cervidés trouvés morts avec un œdème pulmonaire ou une hémorragie et/ou une entéropathie hémorragique.(Traduit par Dr Serge Messier).

Early circulation of rabbit haemorrhagic disease virus type 2 in domestic and wild lagomorphs in southern California, USA (2020-2021).

Rabbit haemorrhagic disease virus type 2 (RHDV2) causes a severe systemic disease with hepatic necrosis. Differently from classic RHDV, which affects only European rabbits (Oryctolagus cuniculus), RHDV2 can affect many leporid species, including hares (Lepus spp.) and cottontail rabbits (Sylvilagus spp.). RHDV2 emerged in Europe in 2010 and spread worldwide. During the last 5 years, there have been multiple outbreaks in North America since the first known event in 2016 in Quebec, Canada, including several detections in British Columbia, Canada, between 2018 and 2019, Washington State and Ohio, USA, in 2018 and 2019, and New York, USA, in 2020. However, the most widespread outbreak commenced in March 2020 in the southwestern USA and Mexico. In California, RHDV2 spread widely across several southern counties between 2020 and 2021, and the aim of this study was to report and characterize these early events of viral incursion and circulation within the state. Domestic and wild lagomorphs (n = 81) collected between August 2020 and February 2021 in California with a suspicion of RHDV2 infection were tested by reverse transcription quantitative real-time PCR on the liver, and histology and immunohistochemistry for pan-lagovirus were performed on liver sections. In addition, whole genome sequencing from 12 cases was performed. During this period, 33/81 lagomorphs including 24/59 domestic rabbits (O. cuniculus), 3/16 desert cottontail rabbits (Sylvilagus audubonii), and 6/6 black-tailed jackrabbits (Lepus californicus) tested positive. All RHDV2-positive animals had hepatic necrosis typical of pathogenic lagovirus infection, and the antigen was detected in sections from individuals of the three species. The 12 California sequences were closely related (98.9%-99.95%) to each other, and also very similar (99.0%-99.4%) to sequences obtained in other southwestern states during the 2020-2021 outbreak; however, they were less similar to strains obtained in New York in 2020 (96.7%-96.9%) and Quebec in 2016 (92.4%-92.6%), suggesting that those events could be related to different viral incursions. The California sequences were more similar (98.6%-98.7%) to a strain collected in British Columbia in 2018, which suggests that that event could have been related to the 2020 outbreak in the southwestern USA.

LEPTOSPIRA PREVALENCE AND ITS ASSOCIATION WITH RENAL PATHOLOGY IN MOUNTAIN LIONS (PUMA CONCOLOR) AND BOBCATS (LYNX RUFUS) IN CALIFORNIA, USA.

Leptospirosis is reported infrequently in wild and domestic felids. We estimated the prevalence of Leptospira spp. infection and exposure using real-time PCR and serology, respectively, in 136 mountain lions (Puma concolor) and 39 bobcats (Lynx rufus) that died or were euthanized between 2009 and 2017 from several regions of California, US. Felids were classified as Leptospira-positive if they were test-positive using real-time PCR targeting the LipL32 gene of pathogenic Leptospira spp. or microscopic agglutination test for six serovars of Leptospira spp. The overall Leptospira spp. prevalence was 46% (63/136) for mountain lions and 28% (11/39) for bobcats. The most common serovar detected in both felid species was Leptospira interrogans serovar Pomona. Age class and geographic location were significantly associated with Leptospira spp. in mountain lions, but not in bobcats. Interstitial nephritis, predominately lymphocytic, was diagnosed in 39% (41/106) of mountain lions and 16% (4/25) of bobcats evaluated histologically and was significantly associated with being Leptospira spp.-positive in both species. Our findings suggest that Leptospira spp. infection is common and widespread in California's wild felids and may have clinical impacts on renal and overall health of individuals. Key words: Bobcat, Leptospira spp., leptospirosis, Lynx rufus, mountain lion, nephritis, pathology, Puma concolor.

Chronic interstitial pneumonia with features of organizing pneumonia in an adult horse.

A 22-y-old American Quarter Horse gelding was presented with a history of chronic progressive respiratory problems and a diffuse pulmonary nodular pattern in thoracic radiographs. The horse was euthanized, and 4 formalin-fixed samples of lung were submitted for histopathology. There were multifocal areas of marked thickening of alveolar septa as a result of proliferation of myofibroblasts embedded in fibromyxoid matrix (interpreted as "Masson bodies"), focal areas of fibrosis, and numerous papillary projections of connective tissue into bronchioles. A diagnosis of organizing pneumonia was reached. No etiology was found for this lesion. It is important to consider causes of chronic interstitial pneumonia with fibrosis in horses other than equid herpesvirus 5, such as complicated viral or bacterial pneumonia or chronic toxicoses.

Clostridium sordellii-associated gas gangrene in 8 horses, 1998-2019.

Gas gangrene occurs in several animal species and is caused by one or more clostridial species. In horses, the disease is most often caused by Clostridium perfringens type A. Although Clostridium sordellii has been associated with gas gangrene in ruminants and humans, cases of the disease associated with this microorganism have not been described in horses, to our knowledge. We report herein 8 cases of gas gangrene caused by C. sordellii in horses. These cases were characterized by myonecrosis and cellulitis, associated with systemic changes suggestive of toxic shock. The diagnosis was confirmed by gross and microscopic changes combined with anaerobic culture, fluorescent antibody test, immunohistochemistry, and/or PCR. The predisposing factor in these cases was an injection or a traumatic skin injury. C. sordellii should be considered as a possible etiologic agent in cases of gas gangrene in horses.

Mycoplasmosis of House Finches ( Haemorhous mexicanus) and California Scrub-Jays ( Aphelocoma californica) in a Wildlife Rehabilitation Facility with Probable Nosocomial Transmission.

We describe an investigation of an outbreak of conjunctivitis in juvenile House Finches ( Haemorhous mexicanus) and California Scrub-jays ( Aphelocoma californica) at a central California, US wildlife rehabilitation facility. In late May 2015, the facility began admitting juvenile finches, the majority with normal eyes at intake. In June, with juvenile finches already present, the facility admitted juvenile scrub-jays, all with normal eyes at intake. In July, after conjunctivitis was observed in increasing numbers of juvenile finches and scrub-jays, carcasses were submitted for postmortem examination. Histopathology of five finches and three scrub-jays identified lymphocytic infiltrates in the ocular tissues. Conjunctival swabs from 87% (13/15) finches and 33% (4/12) scrub-jays were PCR-positive for Mycoplasma gallisepticum. One finch and two scrub-jays were PCR-positive for Mycoplasma synoviae. Additionally, gene sequencing (16S ribosomal RNA and 16S-23S intergenic spacer region) identified Mycoplasma sturni from 33% (3/9) scrub-jays. This outbreak of conjunctivitis suggested that M. gallisepticum-infected juvenile finches admitted to and maintained in a multispecies nursery likely resulted in transmission within the facility to healthy juvenile finches and scrub-jays. Evidence of other Mycoplasma spp. in finches and scrub-jays indicates that these species are susceptible to infection and may act as carriers. This outbreak highlighted the need for effective triage and biosecurity measures within wildlife rehabilitation facilities.

Resistance of colostrum-deprived domestic lambs to infection with deer adenovirus.

Seven colostrum-deprived, 3-4-wk-old Rambouillet-Hampshire lambs were inoculated via the mucous membranes with deer adenovirus (DAdV) and monitored for clinical signs for 21 d post-inoculation at which time animals were euthanized and postmortem examinations were performed. Pre-inoculation and post-inoculation serum samples were tested for antibodies to DAdV, ovine adenovirus 7, bovine adenovirus 7, and goat adenovirus 1. Evidence for DAdV infection was determined by virus isolation, PCR tests, and histopathology with immunohistochemistry tests for DAdV. No clinical signs or lesions consistent with adenoviral hemorrhagic disease (AHD) in deer were seen in the lambs, and the lambs did not seroconvert to DAdV. DAdV was not detected by PCR, virus isolation, or immunohistochemistry in any of the samples tested from the lambs. A positive control deer similarly inoculated with DAdV developed fatal AHD 1 wk post-inoculation. Our colostrum-deprived lambs did not become infected when inoculated with DAdV.

Avian trichomonosis mortality events in band-tailed pigeons (Patagioenas fasciata) in California during winter 2014-2015.

Avian trichomonosis is an upper digestive tract disease of birds typically caused by the protozoan parasite Trichomonas gallinae. In California (U.S.A), trichomonosis is known to cause periodic epidemics in the Pacific Coast band-tailed pigeon (Patagioenas fasciata monolis), a migratory upland game bird. We summarize the mortality events that occurred during winter 2014-2015 including the duration, estimated mortality, pathology, and genetic identity of infecting parasites. Increased mortality was reported from locations in 25 counties between November 2014 and June 2015. Based on reports, carcasses received, wildlife rehabilitation center admissions, site visits, and regular monitoring by local personnel, total mortality was estimated at 18,440. At necropsy, birds had multiple coalescing lesions in the oral cavity involving the upper palate and/or around the tongue and glottis, esophagus, crop, and/or proventriculus. Birds collected from Contra Costa (63.9%; 30/47); Marin (75.0%; 6/8), San Mateo (46.7%; 14/30), and Santa Clara (35.0%; 37/106) counties were more likely to have lesions extending into their head involving muscle, sinuses, ear canals, eye sockets, and bone (χ2 = 62.9; df = 11; P < 0.001). Histopathologic findings included pharyngitis, esophagitis, myositis, and air sacculitis of the pneumatic bone of the skull. Mixed bacterial colonies were found multifocally at the fronts of the necrosis in six of the eleven birds examined histologically. Infecting trichomonads included T. gallinae subtype A2 (n = 5), un-typed T. gallinae (n = 4), mixed infection with T. gallinae subtype A2 and T. stableri (n = 1), and mixed infection with un-typed T. gallinae and T. stableri (n = 1). The winter 2014-2015 epidemic was the largest on record in terms of duration, locations, and birds affected. Infection dynamics may have been exacerbated by the drought in California. Increased monitoring of band-tailed pigeons is needed to understand the long-term impacts of large-scale mortality events on their population.

Adenoviral hemorrhagic disease in California mule deer, 1990-2014.

We reviewed case records from the California Animal Health and Food Safety (CAHFS) laboratory and the California Department of Fish and Wildlife (CDFW) spanning 25 years (1990-2014) for all deer accessions submitted to CAHFS for pathology and/or histopathology, with and without a diagnosis of adenoviral hemorrhagic disease (AHD), in order to determine the prevalence of AHD in California. We also examined spatial and temporal distribution, age, and mule deer subspecies in deer that died from AHD. Of 483 deer submitted to CAHFS for diagnostic testing in 1990-2014, 17.2% were diagnosed with confirmed AHD, and 26.5% were confirmed plus suspected cases of AHD. Columbian black-tailed deer ( Odocoileus hemionus columbianus), particularly fawns and juveniles, were most frequently affected. Deer adenovirus ( Odocoileus adenovirus 1; OdAdV-1) was detected by immunohistochemistry in archived CDFW formalin-fixed, paraffin-embedded tissues from deer that died in mortality events in 1981, 1983, and 1986-1987. OdAdV-1 is a common cause of hemorrhagic disease mortality events in California deer, and mortality as a result of AHD is documented as early as 1981.

Detection of bluetongue virus in Brazilian cervids in São Paulo state / Detecção de vírus da língua azul em cervídeos brasileiros no estado de São Paulo

Viral hemorrhagic diseases in cervids occur worldwide and include epizootic hemorrhagic disease (EHD), bluetongue (BT), and adenoviral hemorrhagic disease (AHD). Since gross lesions in all three hemorrhagic diseases are identical (hemorrhagic enteropathy, pulmonary edema, systemic petechial and suffusion hemorrhages), it is necessary to use accurate techniques for a definitive etiologic diagnosis. Archival material (paraffin blocks) at the Department of Veterinary Pathology of FCAV - Unesp was reviewed for lesions of hemorrhagic disease and 42 captive and free-living Brazilian deer were selected to include in this study. Paraffin-embedded tissues were evaluated using immunohistochemistry and tested negative for adenovirus. Using real time RT-PCR, EHD virus was not detected in paraffin-embedded tissues in any of the cases evaluated. The same technique was used for detection of BT virus and seven positive animals (16,66%) were confirmed after agarose 4% gel electrophoresis and gene sequencing. The main macroscopic changes observed in the positive animals were hemorrhagic intestinal contents, reddish mucous membrane of the gastrointestinal tract, ulcers on tongue and petechiae in various organs. Microscopic changes observed were lymphocytic inflammatory infiltrate in liver, kidney and lungs, hemorrhage, and congestion in various organs. All positive cases were from captive animals, three females (two young and one adult), and four young males. This study demonstrates that the bluetongue virus is involved in hemorrhagic disease outbreaks of deer in Brazil.(AU)

Doenças hemorrágicas virais em cervídeos ocorrem no mundo todo e incluem a doença epizoótica hemorrágica (DEH), língua azul (LA), e doença hemorrágica por adenovírus (DHA). Uma vez que as lesões nas três doenças hemorrágicas são idênticas (enteropatia hemorrágica, edema pulmonar, petéquias sistêmicas e sufusões hemorrágicas), é necessário utilizar técnicas precisas para um diagnóstico etiológico definitivo. Material de arquivo (blocos de parafina) do Departamento de Patologia Veterinária da FCAV - Unesp foi revisado para lesões de doenças hemorrágicas e 42 cervídeos brasileiros de cativeiro e de vida livre foram selecionados e incluídos neste estudo. Tecidos embebidos em parafina foram avaliados usando imunohistoquímica e foram negativos para adenovírus. Usando o RT-PCR em tempo real, o vírus da DEH não foi detectado nos tecidos de nenhum dos casos avaliados. A mesma técnica foi utilizada para detecção do vírus da LA e sete animais positivos (16,66%) foram confirmados após eletroforese em gel de agarose a 4% e sequenciamento genético. As principais alterações macroscópicas observadas nos animais positivos foram conteúdo intestinal hemorrágico, mucosa do trato gastrointestinal avermelhada, úlceras na língua e petéquias em vários órgãos. As alterações microscópicas observadas foram infiltrado inflamatório linfocítico em fígado, rins e pulmões, e hemorragia e congestão em vários órgãos. Todos os casos positivos foram de animais de cativeiro, três fêmeas (dois jovens e um adulto), e quatro jovens do sexo masculino. Este estudo demonstra que o vírus da lingual azul está envolvido nos surtos de doença hemorrágica em veados no Brasil.(AU)

Whole-genome sequences of Odocoileus hemionus deer adenovirus isolates from deer, moose and elk are highly conserved and support a new species in the genus Atadenovirus.

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.

SARCOPTIC MANGE IN ENDANGERED KIT FOXES (VULPES MACROTIS MUTICA): CASE HISTORIES, DIAGNOSES, AND IMPLICATIONS FOR CONSERVATION.

The San Joaquin kit fox ( Vulpes macrotis mutica) is a federally endangered small carnivore whose distribution is limited to the San Joaquin Valley in central California. Population decline is due to profound habitat loss, and conservation of all remaining populations is critical. A robust urban population occurs in the city of Bakersfield. In spring of 2013, putative cases of mange were reported in this population. Mites from affected animals were confirmed to be Sarcoptes scabiei morphologically and by DNA sequencing. By the end of 2014, 15 cases of kit foxes with mange had been confirmed. As with other species, sarcoptic mange in kit foxes is characterized by intense pruritus and dermatitis, caused by mites burrowing into the epidermal layers, as well as alopecia, hyperkeratosis, and encrustations, secondary bacterial infections, and finally extreme morbidity and death. Of the 15 cases, six foxes were found dead, six were captured but died during attempted rehabilitation, and three were successfully treated. We have no evidence that untreated kit foxes can recover from mange. Sarcoptic mange constitutes a significant threat to the Bakersfield kit fox population and could pose an even greater threat to this imperiled species if it spreads to populations in nearby natural lands.

Production of a recombinant capsid protein VP1 from a newly described polyomavirus (RacPyV) for downstream use in virus characterization.

Here we describe the methods for production of a recombinant viral capsid protein and subsequent use in an indirect enzyme linked immunosorbent assay (ELISA), and for use in production of a rabbit polyclonal antibody. These reagents were utilized in development and optimization of an ELISA, which established the extent of exposure of free ranging raccoons to a newly described polyomavirus (RacPyV) [1]. Production of a polyclonal antibody has allowed for further characterization of RacPyV, including immunohistochemistry and immunocytochemistry techniques, in order to answer questions about pathogenesis of this virus.

PHOTORECEPTOR DEGENERATION IN A MOUNTAIN LION CUB (PUMA CONCOLOR).

An orphaned 4-mo-old female mountain lion cub ( Puma concolor ) was captured along the coastline in Montaña de Oro State Park in Los Osos, California, USA. Following suspicion that the cub was visually impaired, ophthalmic examination revealed diffuse bilateral retinal atrophy. Due to a poor prognosis, humane euthanasia was elected. Necropsy and histopathological findings were consistent with photoreceptor degeneration. Based on the cub's signalment, history, and histopathology, a genetic or nutritional etiology was suspected, with the former etiology more strongly supported. To the authors' knowledge, this is the first report of photoreceptor degeneration in a wild felid and should be considered in cases of blindness.

Patterns of Natural and Human-Caused Mortality Factors of a Rare Forest Carnivore, the Fisher (Pekania pennanti) in California.

Wildlife populations of conservation concern are limited in distribution, population size and persistence by various factors, including mortality. The fisher (Pekania pennanti), a North American mid-sized carnivore whose range in the western Pacific United States has retracted considerably in the past century, was proposed for threatened status protection in late 2014 under the United States Endangered Species Act by the United States Fish and Wildlife Service in its West Coast Distinct Population Segment. We investigated mortality in 167 fishers from two genetically and geographically distinct sub-populations in California within this West Coast Distinct Population Segment using a combination of gross necropsy, histology, toxicology and molecular methods. Overall, predation (70%), natural disease (16%), toxicant poisoning (10%) and, less commonly, vehicular strike (2%) and other anthropogenic causes (2%) were causes of mortality observed. We documented both an increase in mortality to (57% increase) and exposure (6%) from pesticides in fishers in just the past three years, highlighting further that toxicants from marijuana cultivation still pose a threat. Additionally, exposure to multiple rodenticides significantly increased the likelihood of mortality from rodenticide poisoning. Poisoning was significantly more common in male than female fishers and was 7 times more likely than disease to kill males. Based on necropsy findings, suspected causes of mortality based on field evidence alone tended to underestimate the frequency of disease-related mortalities. This study is the first comprehensive investigation of mortality causes of fishers and provides essential information to assist in the conservation of this species.

Comparison of trace mineral concentrations in tail hair, body hair, blood, and liver of mule deer (Odocoileus hemionus) in California.

Measuring trace mineral concentrations can be an important component of assessing the health of free-ranging deer. Trace mineral concentrations in liver most accurately reflect the trace mineral status of an individual, but, in live animals, whole blood or serum are the most commonly used sample types. Trace minerals measured in serum, such as copper, zinc, and iron, do not always accurately correlate to liver concentrations, and supplementary samples for evaluating the trace mineral status in live deer would be useful. We evaluated the utility of body and tail hair for measuring selenium, copper, zinc, iron, and manganese in free-ranging mule deer (Odocoileus hemionus) by using Spearman rank correlations and linear regression. Correlations were strongest at the time of or shortly after growth of the winter coat and in resident deer. In live deer, strong correlations and moderate linear associations (R (2) = 0.57) were detected between body and tail hair and whole blood selenium in December. In postmortem-sampled deer, a strong correlation and linear association (R (2) = 0.80) were found between liver and body hair selenium in August-November. Results indicate that body hair, if collected during or shortly after growth of the winter coat, can be used as a supplementary sample for measuring selenium concentrations in deer. None of the other correlations and linear associations were found to be sufficiently strong to conclude that hair can reliably be utilized as a complementary sample for measuring these trace mineral concentrations.

HISTOPATHOLOGY AND RISK FACTORS ASSOCIATED WITH NEOTROMBICULA MICROTI INFESTATION IN THE ENDANGERED AMARGOSA VOLE (MICROTUS CALIFORNICUS SCIRPENSIS).

The Amargosa vole (Microtus californicus scirpensis) is a profoundly endangered rodent found only in the Central Mojave Desert, Inyo County, California, US. In 2010, severe cases of trombiculiasis, caused by larval Neotrombicula microti mites, were discovered among voles and sympatric small mammals. We evaluated Amargosa voles and sympatric rodents for infestation with N. microti December 2011-November 2012 and evaluated histopathology of ear tissue from 13 actively N. microti-infested Amargosa voles and 10 Amargosa voles with no gross evidence of current or past infestation. Rodents with current infestation had mites visible on tissue, typically ear pinnae, whereas mites were not seen on rodents with presumptive past infestation, but some of these animals had gross tissue scarring and loss consistent with healing from infestation. Ears from infested voles had severe granulocytic and necrotizing dermatitis, most associated with stylostome fragments, whereas few lesions were present in grossly uninfested voles. There was no association between body condition and infestation or severity of lesions. Significantly more voles were infested (37%) with N. microti than sympatric rodents (3%), suggesting that sympatric rodents do not serve as an important source of N. microti exposure to voles. Although this chigger infestation was common and induced severe localized pathology, we did not detect a fitness cost to infestation and recommend further evaluation of the disease to discern its significance in this conservation context.

Isolation of a Bohle-like iridovirus from boreal toads housed within a cosmopolitan aquarium collection.

A captive 'survival assurance' population of 56 endangered boreal toads Anaxyrus boreas boreas, housed within a cosmopolitan collection of amphibians originating from Southeast Asia and other locations, experienced high mortality (91%) in April to July 2010. Histological examination demonstrated lesions consistent with ranaviral disease, including multicentric necrosis of skin, kidney, liver, spleen, and hematopoietic tissue, vasculitis, and myriad basophilic intracytoplasmic inclusion bodies. Initial confirmation of ranavirus infection was made by Taqman real-time PCR analysis of a portion of the major capsid protein (MCP) gene and detection of iridovirus-like particles by transmission electron microscopy. Preliminary DNA sequence analysis of the MCP, DNA polymerase, and neurofilament protein (NFP) genes demonstrated highest identity with Bohle iridovirus (BIV). A virus, tentatively designated zoo ranavirus (ZRV), was subsequently isolated, and viral protein profiles, restriction fragment length polymorphism analysis, and next generation DNA sequencing were performed. Comparison of a concatenated set of 4 ZRV genes, for which BIV sequence data are available, with sequence data from representative ranaviruses confirmed that ZRV was most similar to BIV. This is the first report of a BIV-like agent outside of Australia. However, it is not clear whether ZRV is a novel North American variant of BIV or whether it was acquired by exposure to amphibians co-inhabiting the same facility and originating from different geographic locations. Lastly, several surviving toads remained PCR-positive 10 wk after the conclusion of the outbreak. This finding has implications for the management of amphibians destined for use in reintroduction programs, as their release may inadvertently lead to viral dissemination.

Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis.

Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning.

West Nile virus and non-West Nile virus mortality and coinfection of American crows (Corvus brachyrhynchos) in California.

American crows are acutely sensitive to West Nile virus (WNV) infection, and crow mortality has been used in WNV surveillance to monitor enzootic transmission. However, non-WNV sources of mortality could reduce the reliability of crow death as a surveillance tool. Here, using a combination of histopathologic, toxicologic, virologic, and molecular techniques we describe causes of mortality in 67 American crows (Corvus brachyrhynchos) that were collected from a population in the Sacramento Valley of California in 2012 and 2013. Evidence of infectious disease was detected in 70% (47/67) of carcasses. The majority of deaths were linked to a suite of non-WNV viral, bacterial, and fungal infections (39%; 23/59 cases), WNV (36%; 24/67 cases), and an acute toxic event (25%; 15/59 cases). Coinfections were detected in 20% (12/59) of birds and frequently were associated with WNV and poxviral dermatitis. Inferences about WNV activity based on crow mortality should be supported by laboratory confirmation because crow mortality frequently can be caused by other infectious diseases or toxic events.