2006 merck/merial - School of Veterinary Medicine - Louisiana State ...

eeding grounds near Minnedosa, MB spring of 2004 and near St. Denis, SK spring of 2005 and 2006. Fall samples werecollected from waterfowl trapped in large bait traps at banding stations south of Moose Jaw, SK in 2004 and 2005. Sampleswere also collected from hunter-killed ducks in fall of 2005. Blood samples (3 ml) were collected from the right jugular veinof live-caught birds and ducks were classified according to age, sex and species. Samples were centrifuged at 4000 rpm for 8minutes and serum was stored for further analysis at -80¨¬C. Serum samples were tested for presence of neutralizingantibodies using WNV-specific blocking ELISA. A sample was considered positive for WNV if the absorbance valuedetermined by ultraviolet spectrophotometry was ¡Â 70% of the absorbance value of the negative reference serum. Betweenspring of 2005 and 2006, 440 samples were collected from Mallards (Anas platyrhynchos), Blue-winged Teal (Anas discors),Northern Pintails (Anas acuta) and Redheads (Aythya americana). Initial results have shown 18% prevalence of WNVantibodies in adult male mallards in fall of 2005 compared to 10% prevalence in spring of 2006. Juvenile male mallards showthe reverse trend, 0% prevalence in fall of 2005 compared to 18.5% prevalence in spring of 2006. Further analysis isunderway to compare trends of male mallard populations to prevalence of WNV antibody in different species, sexes, andages of waterfowl.An Epidemiological Study of Leptospirosis in Champaign County CaninesJacqueline Scapa*, Dr. Marylin Ruiz, Dr. NamJung Jung, and Dr. Carol MaddoxVeterinary Diagnostic Laboratory/Department of Veterinary Pathobiology, College of Veterinary Medicine at theUniversity of Illinois at Urbana, Champaign.Leptospirosis is a bacterial disease caused by any one of sixteen species and 2,000 serovars of the spirocheteLeptospira. This study is designed to examine the correlation between cases of Leptospirosis in the canine population ofChampaign County and ponds or other bodies of water containing Leptospira. Suburban retention ponds in the new housingdevelopments of Champaign County may serve as exposure sites for pets and pet owners who frequent the area on walks orduring other recreational activities. Advanced GIS software and GPS mapping has permitted the selection of ponds based ontheir proximity to cases of canine Leptospirosis.Real-time Polymerase Chain Reaction was used to determine the presence of Leptospira in every pond sampled thusfar, providing evidence that these ponds, contaminated by wildlife with endemic Leptospira infections, may serve as thereservoirs responsible for the infection in canines. Investigation is currently underway to determine if these ponds containpathogenic Leptospira serovars.Epidemiology of feline pathogenic hemoplasma infectionsJeralyn Terry and Dr. Jane Sykes, BVSc(Hons), PhD, DACVIMDepartment of Medicine & EpidemiologySchool of Veterinary Medicine, University of California, DavisUntil recently, only two hemotropic mycoplasmas (hemoplasmas) were identified as causes of feline infectiousanemia: Mycoplasma haemofelis (Mhf) and Candidatus Mycoplasma haemominutum (Mhm). Recently, a third type ofhemoplasma was identified as being prevalent in Swiss cats, which has been named Candidatus Mycoplasma turicensis(Mtc). In addition, an organism related to the newly discovered canine organism, Candidatus Mycoplasma haematoparvum(Mhp-like) was identified in two cats presenting to the UC Davis Veterinary Medical Teaching Hospital. Theseepierythrocytic bacteria are best diagnosed using the polymerase chain reaction (PCR), as cytological evaluation of bloodsmears has low sensitivity and specificity. Infection with Mhf or Mtc has been associated with anemia in immunocompetentcats, whereas Mhm appears only to cause anemia in immunosuppressed cats. In addition, Mhm has been described as havinga synergistic effect with underlying retroviral (FeLV) infections in causing anemia and possible progression ofmyeloproliferative disease.We hypothesize that other unidentified types of hemoplasmas may be prevalent in anemic cats throughout theUnited States, and that in contrast to a recent study in Europe, hemoplasma infection is associated with retroviral infection inthe United States. The purpose of this study is to evaluate the prevalence, risk factors, and hematologic variables associatedwith hemoplasma infection in cats suspected to have hemoplasmosis from throughout the United States. Blood smears andEDTA blood samples have now been collected through IDEXX Laboratories from over 300 cats that have had completeblood counts performed from various parts of the United States. All samples will be tested using ELISA assays for FeLV andFIV. DNA will be extracted from samples using automated (Corbett) extraction methods. Each sample will be subjected toboth conventional and real-time PCR for Mhm, Mhf, and Mtc. PCR products from samples testing positive with conventionalbut not real-time PCR will be sequenced to determine whether a novel organism is present. The relationship betweeninfection with each hemoplasma species, signalment, geographic location, CBC results, retroviral status, and whether or notbacteria were visualized on cytology will be determined using appropriate statistical analyses.154