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A Muscovy duckling was presented for necropsy due to ongoing mortalities on a farm. Microscopic examination revealed multisystemic inflammatory lesions with intralesional and intracytoplasmic yeast-like organisms. We identified these agents as yeast belonging to the Order Saccharomycetales based on sequence data obtained from the ribosomal RNA operon.

Infection disséminée à levures (OrdreSaccharomycetales) chez un caneton musqué(Cairina moschata). Un caneton musqué a été présenté pour la nécropsie en raison de mortalités se produisant à une ferme. Un examen microscopique a révélé des lésions inflammatoires multisystémiques par des organismes intralésionnels et intracytoplasmiques s'apparentant à des levures. Nous avons identifié ces agents comme des levures appartenant à l'ordre Saccharomycetales en nous fondant sur des données obtenues auprès de l'opéron ARN risbosomique.(Traduit par Isabelle Vallières).

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Effective, long-term strategies to manage the threat of bovine tuberculosis and brucellosis spillback from northern, diseased bison to the Canadian cattle herd and adjacent disease-free wood bison (Bison bison athabascae) herds have eluded policy makers in recent decades. A controversial plan to depopulate infected herds and repopulate them with disease-free wood bison was rejected in 1990 because of significant public concern. Since then, technical advances in vaccine technology, genetic salvage, selective culling, and diagnostic test development have occurred. Containment strategies to reduce further spread of these diseases are a necessary first step; recent progress has been made in this area, but challenges remain. This progress has produced more options for management of these herds in northern Canada, and it is time to consider wood bison conservation and long-term disease eradication as equally important goals that must satisfy concerns of conservation groups, agriculture sectors, aboriginal groups, and the general public. Management of wildlife disease reservoirs in other areas, including Yellowstone and Riding Mountain national parks, has demonstrated that effective disease management is possible. Although combinations of different strategies, including vaccination, genetic salvage techniques, and selective culling, that use sensitive and specific diagnostic tests may offer alternatives to depopulation/repopulation, they also have logistic constraints and cost implications that will need consideration in a multistakeholder, collaborative-management framework. We feel the time is right for this discussion, so a long-term solution to this problem can be applied.

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Non-suppurative encephalitis occurs sporadically in beef cattle in western Canada, leading to loss of animals. This retrospective study investigated the presence of viral, bacterial, and protozoal antigens or DNA in 37 western Canadian feedlot cattle with non-suppurative encephalitis for which a cause had not been identified. Cases were selected based on the age of the animal (> 7 months), and clinical history of recumbency and depression. The identification of rabies in 1 case stresses the importance of including this viral disease in the list of differential diagnoses. Because there was variation in the severity, distribution, and type of lesions, it is possible that there may be more than 1 cause, but failure to identify an infectious agent might also suggest that non-infectious agents could play a role.

Étude rétrospective de l'encéphalite non suppurative chez les bovins de boucherie de l'Ouest canadien. L'encéphalite non suppurative se produit sporadiquement chez les bovins de boucherie de l'Ouest canadien, ce qui cause une perte d'animaux. Cette étude rétrospective a fait enquête sur la présence d'antigènes viraux, bactériens et protozoaires ou d'ADN dans 37 parcs d'engraissement de l'Ouest canadien atteints de l'encéphalite non suppurative dont la cause n'avait pas été identifiée. Les cas ont été choisis en fonction de l'âge de l'animal (> 7 mois) et de l'anamnèse clinique de décubitus et de dépression. L'identification de la rage dans 1 cas met en lumière l'importance d'inclure cette maladie virale dans la liste des diagnostics différentiels. Parce qu'il y avait une variation au niveau de la gravité, de la répartition et du type de lésions, il est possible qu'il y ait plus d'une cause, mais la non-identification d'un agent infectieux pourrait aussi suggérer que des agents non infectieux pourraient jouer un rôle.(Traduit par Isabelle Vallières).

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An 8-year-old female elk (Cervus elaphus canadensis) cow, presented for chronic severe weight loss and unthriftiness, was diagnosed with Babesia odocoilei infection based on blood smear evaluation, polymerase chain reaction (PCR), and DNA sequence analysis. Subsequently, velvet antler from a male that died acutely on the same farm was also PCR positive for Babesia spp. Both animals originated from a game ranch of Saskatchewan-bred and -raised animals with no known history of tick exposure, but with a history of numerous sudden deaths of unknown etiology. The presence of B. odocoilei in Canada might be a result of a recent introduction that could have deleterious effects on local wild ungulates or may represent discovery of a previously unrecognized endemic disease in local wildlife.

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Adults of the flea, Ceratophyllus vagabundus vagabundus , were present in the hundreds in nests of Ross's (Chen rossii) and lesser snow (Chen caerulescens caerulescens) geese in the Arctic goose colony at Karrak Lake, Nunavut, Canada. Ceratophyllus v. vagabundus had not been previously recorded in association with Ross's or snow geese. Large numbers of C. v. vagabundus adults and larvae were collected and a description of the larva is provided for the first time. On the basis of external characters, larvae were indistinguishable from those of a number of other Ceratophyllus spp. previously described from North America, i.e., Ceratophyllus idius, Ceratophyllus niger, and Ceratophyllus lari.

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An outbreak of bovine tuberculosis was detected in the Hook Lake Wood Bison Recovery Project captive-breeding herd in March 2005. This study investigates the most likely source of Mycobacterium bovis and identifies difficulties associated with salvaging tuberculosis-free animals from an endemically infected herd.

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This retrospective study evaluated epidemiologic features and disease associations of feline immunodeficiency virus (FIV) infection in client owned cats from western Canada. Among 1205 cats that were tested 66 (5.5%) were positive for FIV antibody (FIV(+)) with a higher prevalence in males than females. FIV(+) cats were older than the overall population. Epidemiologic features and disease associations were compared between 58 FIV(+), but feline leukemia virus negative (FeLV(-)) cats and 58 age and sex matched FIV-negative (FIV(-)), FeLV(-) cats. FIV positivity was associated with a history of bite wounds, increasing age, and male gender. Lethargy and oral diseases were significantly associated with FIV positivity. Although several FIV(+) cats were euthanized, the survival time of FIV(+) cats after diagnosis was not significantly different from that of FIV(-) cats. In summary, FIV prevalence was low in cats from western Canada, clinical signs/diseases were mild, and lifespan was not different in FIV(+) cats.

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Intracellular organisms in the endothelial cells of several organs of an adult great blue heron (Ardea herodias) were identified as a yeast in the family Saccharomycetales based on ultrastructural morphology and sequence data from the ribosomal RNA operon. Morphologically similar organisms of unknown identity have been described previously in Muscovy (Cairina moschata) and domestic (Anas platyrhynchos domestica) ducks.

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Severe meningoencephalitis and endometritis associated with necrotizing vasculitis, thrombosis, and infarction were found at necropsy of a 4-year-old Aberdeen Angus cow with a history of abortion and neurological signs. Focal pyogranulomatous pneumonia and nephritis were also present. Fungal hyphae typical of zygomycetes were abundant within lesions, and Mortierella wolfii was cultured from multiple tissues. This is believed to be the first report of systemic mortierellosis following abortion in North America, and the second reported instance of encephalitis caused by M. wolfii in a cow.

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A portion of retropharyngeal lymph nodes from 6,824 wild cervids, comprising 1,458 white-tailed deer (Odocoileus virginianus), 5,345 mule deer (Odocoileus hemionus), 11 unidentified deer (Odocoileus spp.), and 10 elk (Cervus elaphus), were examined histologically for evidence of inflammation. Focal granulomatous lymphadenitis was detected in 0.3% of white-tailed deer, 1.3% of mule deer, and in one of 10 elk. Material consistent with Splendore-Hoeppli phenomenon was present in 70 (93%) of 75 cases of lymphadenitis. Replicate sections stained with Gram, acid fast, and methenamine silver stains were examined for organisms. Organisms morphologically consistent with Actinomyces spp. were found in one white-tailed deer; no organisms were detected in any of the other cases of lymphadenitis. Aerobic and anaerobic culture from frozen tissue from the lymph nodes was negative, as was polymerase chain reaction (PCR) for Mycobacterium spp. and Mycobacterium bovis. The method of sampling likely underestimated the prevalence of lymphadenitis.

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This report describes West Nile virus (WNV)-associated mortality in captive lesser scaup (Aythya affinis) ducklings that occurred in Saskatchewan, Canada, in July and August 2007. There were no clinical signs or gross necropsy findings suggestive of the cause of death; however, microscopic lesions were consistent with WNV infection, including nonsuppurative encephalitis and myocardial, pancreatic, and splenic necrosis. Necrosis of the thymus and thyroid was also observed in some birds, which has not previously been reported in association with WNV infection. Immunohistochemistry revealed WNV antigen in multiple tissues, including thymus and thyroid, and reverse transcription polymerase chain reaction resulted in the identification of WNV gene sequence in all of the ducklings that were tested. This outbreak is of interest because waterfowl (Anseriformes) are not thought to be particularly susceptible to WNV, and there is little information about WNV infection in prefledging birds. The apparent susceptibility of lesser scaup to WNV demonstrated in this study may have implications for declining lesser scaup populations in the wild.

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Mycobacterium bovis infection in wild animals attracted little attention in Canada until the disease was almost eliminated from domestic livestock. Tuberculosis was endemic in plains bison and occurred in elk, moose, and mule deer in Buffalo National Park (BNP), Alberta during the 1920s and 1930s. Bison were moved from BNP to Wood Buffalo National Park (WBNP), where tuberculosis became, and remains, endemic in bison, posing a risk to efforts to restore bison in northern Canada. Tuberculosis was found in a white-tailed deer in Ontario in 1959, and in an infected elk near Riding Mountain National Park (RMNP), Manitoba in 1992. Intense surveillance has resulted in detection of 40 elk, 8 white-tailed deer, and 7 cattle herds infected between 1997 and 2008 in the RMNP area. The strains of M. bovis in the RMNP area are different from strains tested from cattle and bison elsewhere in Canada. Management of tuberculosis in cattle and wild animals is challenging because of uncertainty about the ecology of the disease in various species, difficulty in obtaining samples and population data from wildlife, lack of validated tests, overlapping jurisdictions and authority, and conflicting values and opinions among stakeholders.

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Information related to infection of wild rodents or lagomorphs in Canada by Francisella tularensis, Yersinia pestis, other Yersinia spp., and Clostridium piliforme was searched for this study. Reports on tularemia in humans linked to these species came from diagnostic databases, literature, wildlife health specialists, and public health agencies. Tularemia has been diagnosed in 8 species of wild rodent and 2 species in the genus Lepus in Canada. Tularemia occurred in wild animals, or in humans associated with these species, in all jurisdictions except the Yukon and Nunavut. Tularemia was diagnosed most frequently in beaver, muskrats, and snowshoe hares, and although tularemia is closely linked to cottontail rabbits in the USA, it has not been reported in cottontails in Canada. Tularemia in humans was associated with muskrats and hares more commonly than with beaver. Plague was diagnosed in bushy-tailed woodrats in British Columbia in 1988. Based on surveys, Y. pestis may occur enzootically in southern Alberta, Saskatchewan, and British Columbia. Infection with Yersinia pseudotuberculosis and Y. enterocolitica has been diagnosed in beaver, muskrats, and snowshoe hares in many provinces. Tyzzer's disease has been diagnosed in muskrats in British Columbia, Saskatchewan, Ontario, and Quebec and in snowshoe hares in Ontario. Infection with these bacteria is likely much more frequent than indicated by diagnostic records.

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Malignant catarrhal fever (MCF)-like disease was diagnosed at postmortem in 2 Stone's sheep (Ovis dalli stonei). On gross examination, the predominant abnormality in both sheep was severe perirenal hemorrhage and multiple renal infarcts. Microscopically, there was severe, multisystemic lymphocytic arteritis. Both sheep were positive for Ovine herpesvirus 2 (OvHV-2) on polymerase chain reaction, and partial sequencing of the viral DNA polymerase genes from the 2 sheep revealed >99% homology, with 96% similarity to the reference GenBank OvHV-2 viral sequence. Based on the histological lesions, polymerase chain reaction results, and viral DNA polymerase gene sequencing, a diagnosis of OvHV-2-mediated MCF was made. Massive perirenal hemorrhage has not been described previously as a manifestation of MCF.

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Infestation of deer with Demodex spp. mites has been described in white-tailed deer (Odocoileus virginianus) and in Columbian black-tailed deer (Odocoileus hemionus columbianus) in North America, as well as in four species of deer in Europe. We describe Demodex sp. infestation in an adult female mule deer (Odocoileus hemionus hemionus) with skin lesions found dead near Saskatoon, Saskatchewan, Canada. This is believed to be the first report of demodicosis in mule deer.

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Elk (Cervus elaphus manitobensis) and white-tailed deer (Odocoileus virginianus) in the Riding Mountain National Park (RMNP) region of southwestern Manitoba have been identified as a likely wildlife reservoir of Mycobacterium bovis, the causative agent of bovine mycobacteriosis in livestock. The feasibility of using coyotes (Canis latrans) collected from trappers as a sentinel species was investigated. Retropharyngeal, mesenteric, and colonic lymph nodes and tonsils collected at necropsy from 82 coyotes were examined by bacterial culture, polymerase chain reaction (PCR), and acid-fast histopathology. Mycobacterium bovis was not identified in any animal by culture or PCR although Mycobacterium avium species were isolated. A single acid-fast organism was identified on histopathologic examination of one animal. Based on the methods used in this study, trapper-caught coyotes do not appear to be a sensitive sentinel species of M. bovis infection in cervids in and around RMNP.

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The diversity and dynamics of Bartonella genotypes found in wild Richardson's ground squirrels (RGS), Spermophilus richardsonii were monitored at multiple sites in Saskatchewan, Canada from 2002 to 2004. Based on sequence analysis of a portion of the Bartonella citrate synthase (gltA) gene, four different genotypes were detected in 233 isolates from 176 animals. The majority (87%) of sequences were identified as genotype H, with genotypes I, J, and K accounting for 8%, 4%, and 1% of sequences, respectively. Only one animal was concurrently infected with multiple Bartonella genotypes. Of 23 animals sampled four times or more, 26% were never infected with Bartonella. Of 32 RGS infected with Bartonella at first capture and then sampled again the following month, 50% were infected with the same Bartonella genotype, 41% were no longer infected, and 9% were infected with a different Bartonella genotype in the subsequent sample. The diversity of Bartonella genotypes varied among sites. At one site almost all RGS were infected with genotype H in September, and up to 60% of the same population was infected with genotype I the following spring. We compare our results with previous studies of Bartonella infections in rodents and discuss possible explanations for the observed differences.

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