Gary Wobeser

Publications of Gary Wobeser

• Intracellular yeasts in endothelial cells of a great blue heron (Ardea herodias).

  Authors: Caroline Millins, Janet E Hill, Gary Wobeser

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 01/2010; 22(1):131-4.

  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 ultrastructuralIntracellular 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.

• Tularemia, plague, yersiniosis, and Tyzzer's disease in wild rodents and lagomorphs in Canada: a review.

  Authors: Gary Wobeser, G Douglas Campbell, André Dallaire, Scott McBurney

  The Canadian veterinary journal. La revue vétérinaire canadienne. 12/2009; 50(12):1251-6.

  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.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.

• Bovine tuberculosis in Canadian wildlife: an updated history.

  Authors: Gary Wobeser

  The Canadian veterinary journal. La revue vétérinaire canadienne. 11/2009; 50(11):1169-76.

  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 andMycobacterium 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.

• Cyathostominosis in a horse from Saskatchewan.

  Authors: Gary Wobeser, Audrey Tataryn

  The Canadian veterinary journal. La revue vétérinaire canadienne. 10/2009; 50(10):1099-100.

• Granulomatous inflammation in retropharyngeal lymph nodes of wild cervids in Saskatchewan.

  Authors: Jung-To Chiu, Gary Wobeser, Trent Bollinger

  Journal of wildlife diseases. 08/2009; 45(3):625-30.

  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 (OdocoileusA 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.

• Destructive Polyarthritis In Aborted Bovine Fetuses: A Possible Association with Ureaplasma diversum infection?

  Authors: Chelsea Himsworth, Janet Hill, Yanyun Huang, Edwin Waters, Gary Wobeser

  Veterinary pathology. 02/2009;

  Severe destructive polyarthropathy with fibrillation and erosion of articular cartilage, deformation of articular surfaces, and proliferation of periarticular soft tissue, was diagnosed in 5 bovineSevere destructive polyarthropathy with fibrillation and erosion of articular cartilage, deformation of articular surfaces, and proliferation of periarticular soft tissue, was diagnosed in 5 bovine fetuses aborted in the last trimester. There was involvement of a single coxofemoral joint in 2 fetuses, both elbows and a stifle in 1, both stifles and tarsal joints in another, and, in the most severely affected fetus, both hips, stifles, and shoulders, as well as 1 carpus. In affected joints, the articular cartilage was irregularly reduced in thickness and contained fibrovascular tissue and, in some cases, inflammatory cells and fibrin. Four of 5 fetuses had microscopic placentitis; all had mild lymphoplasmacytic conjunctivitis. Ureaplasma spp. was identified in 4 cases by polymerase chain reaction or culture. Fetal arthropathy and Ureaplasma diversum-associated joint pathology have not been previously reported in the veterinary literature; however, other Ureaplasma spp. are known to cause reproductive disease and arthritis in humans.

• Bilateral perirenal hemorrhage in two Stone's sheep (Ovis dalli stonei): a possible manifestation of malignant catarrhal fever.

  Authors: Chelsea G Himsworth, N Jane Harms, Gary Wobeser, Janet Hill

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 09/2008; 20(5):676-8.

  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 perirenalMalignant 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.

• Demodicosis in a mule deer (Odocoileus hemionus hemionus) from Saskatchewan, Canada.

  Authors: Marie-Line Gentes, Heather Proctor, Gary Wobeser

  Journal of wildlife diseases. 11/2007; 43(4):758-61.

  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, asInfestation 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.

• Feasibility of using coyotes (Canis latrans) as sentinels for bovine mycobacteriosis (Mycobacterium bovis) infection in wild cervids in and around Riding Mountain National Park, Manitoba, Canada.

  Authors: Cheryl Sangster, Doug Bergeson, Cyril Lutze-Wallace, Vince Crichton, Gary Wobeser

  Journal of wildlife diseases. 08/2007; 43(3):432-8.

  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 wildlifeElk (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.

• Isolation of Mycobacterium bovis from a wood bison in a wildlife conservation project in the Northwest Territories.

  Authors: Cyril Lutze-Wallace, Claude Turcotte, Dan A Stevenson, Brett Elkin, Maria Koller-Jones, John Nishi, Gary Wobeser

  The Canadian veterinary journal. La revue vétérinaire canadienne. 05/2006; 47(4):317-8.

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• Diversity of Bartonella genotypes in Richardson's ground squirrel populations.

  Authors: Claire Jardine, Dorothy McColl, Gary Wobeser, Frederick A Leighton

  Vector borne and zoonotic diseases (Larchmont, N.Y.). 02/2006; 6(4):395-403.

  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 toThe 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.

• Investigation of a syndrome of sudden death, splenomegaly, and small intestinal hemorrhage in farmed deer.

  Authors: Carissa K Embury-Hyatt, Gary Wobeser, Elemir Simko, Murray R Woodbury

  The Canadian veterinary journal. La revue vétérinaire canadienne. 09/2005; 46(8):702-8.

  A newly recognized syndrome, characterized by sudden death of farmed deer that are in good to excellent nutritional condition, with lesions of small intestinal mucosal hemorrhage and splenomegaly, isA newly recognized syndrome, characterized by sudden death of farmed deer that are in good to excellent nutritional condition, with lesions of small intestinal mucosal hemorrhage and splenomegaly, is described. Other frequently observed lesions were small intestinal mucosal necrosis, abomasal hemorrhage, random hepatic necrosis, and multifocal hepatic congestion. Clostridium perfringens type A was isolated in high numbers from the intestines of many of the deer affected by the syndrome; however, the numbers were not significantly different from those of control deer. The syndrome did not appear to be related to dietary or any other specific management factors and a definitive cause of the syndrome was not identified.

• Rodent-associated Bartonella in Saskatchewan, Canada.

  Authors: Claire Jardine, Greg Appleyard, Michael Y Kosoy, Dorothy McColl, Manuel Chirino-Trejo, Gary Wobeser, Frederick A Leighton

  Vector borne and zoonotic diseases (Larchmont, N.Y.). 02/2005; 5(4):402-9.

  Six species of wild rodents were sampled at 10 sites in 2002 and 2003 to determine the prevalence of Bartonella infections in rodent communities near Saskatoon, Saskatchewan, Canada. Isolates wereSix species of wild rodents were sampled at 10 sites in 2002 and 2003 to determine the prevalence of Bartonella infections in rodent communities near Saskatoon, Saskatchewan, Canada. Isolates were characterized genotypically and compared with isolates found at other locations. Of 104 wild rodents examined, 57% were infected with Bartonella and prevalence within species varied from 49% for Richardson's ground squirrels (Spermophilus richardsonii) to 90% for Franklin's ground squirrels (S. franklinii). Infected rodents were found at all sites. Sequencing of a 379-bp portion of the citrate synthase gene was performed on 54 isolates and revealed 13 distinct genotypes, eight of which had not been described previously. The most common genotype detected in red-backed voles (Clethrionomys gapperi) was 99.1% similar to B. grahamii, a known human pathogen. Two of 10 Franklin's ground squirrels were concurrently infected with multiple Bartonella genotypes. All genotypes, with the exception of one detected in both Franklin's and thirteen-lined ground squirrels (S. tridecemlineatus), were found in only one host, and all genotypes from each species, with the exception of genotypes detected in red-backed voles, clustered together within the same relatedness group, suggesting that at least some Bartonella genotypes are specific to some rodent hosts.

• Malignant melanoma in a captive red deer (Cervus elaphus elaphus).

  Authors: Brad Scandrett, Gary Wobeser

  Journal of wildlife diseases. 11/2004; 40(4):808-10.

  We report a case of malignant melanoma in a captive red deer (Cervus elaphus elaphus). The primary lesion was on the plantar aspect of the right pastern and infiltrated the surrounding skin, but notWe report a case of malignant melanoma in a captive red deer (Cervus elaphus elaphus). The primary lesion was on the plantar aspect of the right pastern and infiltrated the surrounding skin, but not underlying tendons or bone. Diffuse metastasis to the regional lymph nodes had occurred. Histologically, lesions were characterized by large numbers of variably pigmented epithelioid cells with a high degree of nuclear atypia and many mitotic figures. This is the first reported case of this neoplasm in red deer.

• Renal lipomatosis in a lamb.

  Authors: Gary Wobeser, Shawn Haas

  The Canadian veterinary journal. La revue vétérinaire canadienne. 11/2004; 45(10):863-4.

• Coinfection with bovine viral diarrhea virus and Mycoplasma bovis in feedlot cattle with chronic pneumonia.

  Authors: Farshid M Shahriar, Edward G. Clark, Eugene Janzen, Keith West, Gary Wobeser

  The Canadian veterinary journal. La revue vétérinaire canadienne. 12/2002; 43(11):863-8.

  Chronic, antibiotic-resistant pneumonia, sometimes with concurrent polyarthritis, occurs in feedlot cattle in western Canada. The prevalence of Mycoplasma bovis, bovine viral diarrhea virus, andChronic, antibiotic-resistant pneumonia, sometimes with concurrent polyarthritis, occurs in feedlot cattle in western Canada. The prevalence of Mycoplasma bovis, bovine viral diarrhea virus, and Haemophilus somnus was determined by using immunohistochemical staining of lung and heart tissue from 2 groups of animals with this history. Mycoplasma bovis antigen was present in 44/48 cases submitted between 1995 and 1998 (retrospective group) and 15/16 of cases from 1999 (prospective group), and was associated with pulmonary necrosis. Bovine viral diarrhea virus antigen was present in association with microscopic vascular lesions in 31/48 retrospective and 9/16 of prospective cases. Types Ib and II bovine viral diarrhea virus were isolated from 4/16 prospective cases. Haemophilus somnus antigen was present in heart, lung, or both of 15/48 retrospective and 8/16 prospective cases. The results suggest that there may be synergism between bovine viral diarrhea virus and M. bovis in this pneumonia with arthritis syndrome.

• New and emerging diseases--the wildlife interface.

  Authors: Gary Wobeser

  The Canadian veterinary journal. La revue vétérinaire canadienne. 11/2002; 43(10):798.