Publications

prevalence of antibodies to leptospira in wild mammals trapped on livestock farms in ontario, canada.	to determine the prevalence and diversity of leptospira serogroups circulating in wildlife on farms in ontario, we tested samples from 51 raccoons (procyon lotor), seven skunks (mephitis mephitis), four rats (rattus norvegicus), and three opossums (didelphis virginiana) that were trapped on 27 livestock (swine [sus scrofa], cattle [bos taurus]) farms in 2010. seventeen of 51 raccoons (33%; 95% confidence interval [ci], 21-48%) sampled were positive for at least one leptospira serogroup using the ...	2014	24807356
suitability and limitations of portion-specific abattoir data as part of an early warning system for emerging diseases of swine in ontario.	abstract: background: abattoir data have the potential to provide information for geospatial disease surveillance applications, but the quality of the data and utility for detecting disease outbreaks is not well understood. the objectives of this study were to 1) identify non-disease factors that may bias these data for disease surveillance and 2) determine if major disease events that took place during the study period would be captured using multi-level modelling and scan statistics. we analy ...	2012	22225910
porcine reproductive and respiratory syndrome virus in ontario, canada 1999 to 2010: genetic diversity and restriction fragment length polymorphisms.	classification of ontario porcine reproductive and respiratory syndrome virus (prrsv) field isolates (n?=?505) from 1999 to 2010, based on a global type 2 prrsv orf5 phylogenetic framework, revealed genetic diversity comparable to prrsv in the usa, with sequences assigned to five of nine lineages (1, 2, 5, 8 and 9). importantly, the tree topology indicated a canadian ancestry for the highly virulent mn184-related strains that first emerged in 2001 in the usa. mapping of the rflp patterns onto th ...	2011	21346028
preliminary investigations of the distribution of escherichia coli o149 in sows, piglets, and their environment.	little is known about the sources and kinetics of enterotoxigenic escherichia coli colonization in pigs during the pre-and post-weaning period. in this study, farrowing pens, sows, and piglets were tested for the presence of e. coli o149 by real-time polymerase chain reaction (pcr) after bacterial culture pre-enrichment on 2 farms, one with a history of post-weaning diarrhea (problem farm - pf) and the other without such a history (non-problem farm - npf). unlike those on the pf, the sows from t ...	2011	21461196
patterns of condemnation rates in swine from a federally inspected abattoir in relation to disease outbreak information in ontario (2005-2007).	strong correlations between clinical signs on farms and the presence of lesions at slaughter have been reported. the objective of this study was to determine if changes in condemnation rates provide a data source for surveillance of disease outbreaks in pigs. the data were obtained from 1 abattoir in ontario (2005-2007). the epidemiological relevance of the results was based on an outbreak of porcine circovirus associated disease (pcvad) in ontario in 2005. the total condemnations and condemnati ...	2011	21461204
an observational study on the prevalence and impact of isospora suis in suckling piglets in southwestern ontario, and risk factors for shedding oocysts.	an observational study was conducted to determine the prevalence of isospora suis oocysts in fecal samples from suckling piglets in ontario, and to evaluate the relationship between the presence of i. suis oocysts and diarrhea. fifty farms and 709 litters of piglets were included in the study. oocysts were detected on 70% of farms, with 187 litters infected. a litter of pigs that was positive for oocysts was significantly more likely to exhibit diarrhea than a litter that was negative [odds rati ...	2011	21532828
phylogenetic networks to study the origin and evolution of porcine circovirus type 2 (pcv2) in cuba.	porcine circovirus type 2 (pcv2) is the essential etiological infectious agent of postweaning multisystemic wasting syndrome (pmws), which is considered one of the most economically important swine diseases worldwide. in this study, a comparison between methodologies based on classical phylogenetic trees and networks to infer the origin of pcv2 in cuba was performed. in addition, the mechanisms supporting the genetic variability of cuban pcv2 populations were investigated. a retrospective study, ...	2011	21507587
analytical and clinical validation of novel real-time reverse transcriptase-polymerase chain reaction assays for the clinical detection of swine-origin h1n1 influenza viruses.	during the early stages of the 2009/2010 swine-origin h1n1 influenza a (s-oiv h1n1 flua) outbreak, the development and validation of sensitive and specific detection methods were a priority for rapid and accurate diagnosis. between may and june 2009, 2 real-time reverse transcriptase-polymerase chain reaction (rrt-pcr) assays targeting the hemagglutinin and neuraminidase genes of the s-oiv h1n1 flua virus were developed. these assays are highly specific, showing no cross-reactivity against a pan ...	2011	21251560
estimating background rates of guillain-barre syndrome in ontario in order to respond to safety concerns during pandemic h1n1/09 immunization campaign.	abstract: background: the province of ontario, canada initiated mass immunization clinics with adjuvanted pandemic h1n1 influenza vaccine in october 2009. due to the campaign's scale, temporal associations with guillain-barre syndrome (gbs) and vaccination were expected. the objectives of this analysis were to estimate the number of background gbs cases expected to occur in the projected vaccinated population and to estimate the number of additional gbs cases which would be expected if an associ ...	2011	21586163
microbiological identification and analysis of swine tonsils collected from carcasses at slaughter.	the primary objective of this 7-month study was to determine the prevalence of porcine pathogens of the tonsil of the soft palate of swine at slaughter. additional objectives were to determine if sampling the carcasses of normal or abnormal hogs provided different microbiological profiles and if the slaughter plant provides a feasible sampling frame and environment for detecting and monitoring important pathogens in tonsils that have health implications for both swine and humans. a total of 395 ...	2011	21731180
antimicrobial susceptibility of clostridium perfringens isolates of bovine, chicken, porcine, and turkey origin from ontario.	antimicrobial susceptibilities and toxin types were determined for 275 clostridium perfringens isolates collected in ontario in the spring of 2005. minimal inhibitory concentrations (mics) of c. perfringens isolates for 12 antimicrobials used in therapy, prophylaxis, and/or growth promotion of cattle (n = 40), swine (n = 75), turkeys (n = 50), and chickens (n = 100) were determined using the microbroth dilution method. statistical analyses and mic distributions showed reduced susceptibility to b ...	2011	21731178
prevalence of yersinia enterocolitica shedding and bioserotype distribution in ontario finisher pig herds in 2001, 2002, and 2004.	we investigated characteristics of yersinia enterocolitica infection in ontario finisher pig herds. our specific objectives were to estimate or test: prevalence of y. enterocolitica shedding in finisher pigs, bioserotype distribution, agreement between the herd-level tests based on sampling pig and pooled fecal samples, whether bioserotypes cluster by farms, and whether y. enterocolitica-positive herds cluster spatially. in total, 3747 fecal samples were collected from 100 farms over the years 2 ...	2010	19926152
preliminary studies into the characterization of chemical markers of decomposition for geoforensics.	in this paper, we report the results of our preliminary studies into chemical characterization of the fluids produced during decomposition in the absence of a soil matrix. pig (sus domestica) carcasses were used to model the human decomposition process in two separate locations, western australia (perth) and canada (oshawa). analysis involved simple dilution and filtration of the decomposition fluids followed by gas chromatography-mass spectrometry. several previously unreported compounds were d ...	2010	20070470
management factors associated with farrowing rate in commercial sow herds in ontario.	the objectives of this study were to determine associations between low farrowing rate and various management factors in sow herds. in 30 sow herds, a management survey, breeding observations, semen evaluation, and semen storage temperature monitoring were completed. herds with an average farrowing rate of < 85% were classified as low farrowing rate herds while those with an average farrowing rate of > or = 85% were classified as good farrowing rate herds. low farrowing rate herds were more like ...	2010	20436865
examination of adipocere formation in a cold water environment.	adipocere is a late-stage postmortem decomposition product that forms from the lipids present in soft tissue. its formation in aquatic environments is typically related to the presence of a moist, warm, anaerobic environment, and the effect of decomposer microorganisms. the ideal temperature range for adipocere formation is considered to be 21-45 degrees c and is correlated to the optimal conditions for bacterial growth and enzymatic release. however, adipocere formation has been reported in coo ...	2010	20437052
ammonia emissions from livestock industries in canada: feasibility of abatement strategies.	an updated national ammonia (nh(3)) emissions inventory was employed to study the relationship between nh(3) emissions and livestock industries in canada. emissions from animal agriculture accounted for 322kilotonnes (kt) or 64% of canadian nh(3) emissions in 2002. cattle and swine accounted for the bulk of livestock emissions. the provinces of alberta, ontario, quebec, and saskatchewan accounted for 28.1%, 22.0%, 18.7%, and 13.1% of total livestock emissions, respectively. emissions from ontari ...	2010	20542610
distribution of genotypes of porcine reproductive and respiratory syndrome virus in ontario during 2004-2007 and the association between genotype and clinical signs of disease.	restriction fragment length polymorphism (rflp) was first proposed to classify porcine reproductive and respiratory syndrome virus (prrsv) in 1998. the primary objective of this study was to identify associations between different prrsv rflp types in swine herds in southern ontario and clinical signs of disease in those herds. herds included in the study submitted samples to the animal health laboratory at the university of guelph between september 2004 and august 2007. each farm owner was surve ...	2010	20592841
prevalence of salmonella infecting bacteriophages associated with ontario pig farms and the holding area of a high capacity pork processing facility.	there is interest in applying bacteriophages to control salmonella in pig production and pork processing. the following reports on the prevalence of salmonella infecting bacteriophages within ontario pig farms and associated with the holding area of a pork slaughterhouse.	2010	20661898
evaluation of the risk factors for shedding salmonella with or without antimicrobial resistance in swine using multinomial regression method.	a multinomial logistic regression method was used to investigate the risk factors for antimicrobial resistance (amr) in salmonella isolated from faecal samples collected on 80 ontario swine farms in canada. the samples were classified into three groups including salmonella-negative samples (s-), salmonella-positive samples without amr (s+amr-) and salmonella-positive samples with amr (s+amr+). the samples collected directly from pigs had a greater chance to be positive for salmonella with amr co ...	2010	21083821
spread of porcine circovirus associated disease (pcvad) in ontario (canada) swine herds: part ii. matched case-control study.	the emergence of porcine circovirus associated disease (pcvad) was associated with high mortality in swine populations worldwide. studies performed in different regions identified spatial, temporal, and spatio-temporal trends as factors contributing to patterns of the disease spread. patterns consistent with spatial trend and spatio-temporal clustering were already identified in this dataset. on the basis of these results, we have further investigated the nature of local spread in this report. t ...	2010	21190586
evaluation of a veterinary-based syndromic surveillance system implemented for swine.	practicing veterinarians play an important role in detecting the initial outbreak of disease in animal populations. a pilot study was conducted to determine the feasibility of a veterinary-based surveillance system for the ontario swine industry. a total of 7 practitioners from 5 clinics agreed to submit information from july 1, 2007 to june 30, 2008. the surveillance program was evaluated in terms of timeliness, compliance, geographic coverage, and data quality. our study showed that the veteri ...	2010	21197223
spread of porcine circovirus associated disease (pcvad) in ontario (canada) swine herds: part i. exploratory spatial analysis.	the systemic form of porcine circovirus associated disease (pcvad), also known as postweaning multisystemic wasting syndrome (pmws) was initially detected in the early 1990s. starting in 2004, the canadian swine industry experienced considerable losses due to pcvad, concurrent with a shift in genotype of porcine circovirus type 2 (pcv2). objectives of the current study were to explore spatial characteristics of self-reported pcvad distribution in ontario between 2004 and 2008, and to investigate ...	2010	21190587
occurrence of salmonella, campylobacter, yersinia enterocolitica, escherichia coli o157 and listeria monocytogenes in swine.	the objective of this study was to investigate the occurrence of major bacterial foodborne pathogens in swine. in total, 359 samples from manure storage tanks (91) and fresh pooled faeces (268) obtained from finisher (110), sows (78) and weanlings (80) were collected and tested. campylobacter, salmonella, yersinia enterocolitica, escherichia coli o157 and listeria monocytogenes were isolated from 36.5%, 31.5%, 5.8%, 3.3% and 3.3% of samples respectively. all e. coli o157 isolates found on 10 far ...	2010	19638163
knowledge of zoonoses among those affiliated with the ontario swine industry: a questionnaire administered to selected producers, allied personnel, and veterinarians.	zoonoses are diseases caused by infectious agents that are transmitted from animals to humans. some zoonoses have been associated with the pig and pork industry. to ensure the safety of pigs and pork and to improve public health it is essential to understand the level of knowledge of those affiliated with the swine industry. the purpose of our study was to assess the knowledge of and attitude toward zoonotic and other microbial hazards among targeted groups of stakeholders associated with the on ...	2010	19895261
optimal pandemic influenza vaccine allocation strategies for the canadian population.	the world is currently confronting the first influenza pandemic of the 21(st) century. influenza vaccination is an effective preventive measure, but the unique epidemiological features of swine-origin influenza a (h1n1) (ph1n1) introduce uncertainty as to the best strategy for prioritization of vaccine allocation. we sought to determine optimal prioritization of vaccine distribution among different age and risk groups within the canadian population, to minimize influenza-attributable morbidity a ...	2010	20463898
potential pediatric intensive care unit demand/capacity mismatch due to novel ph1n1 in canada.	to investigate the possibility of pediatric intensive care unit shortfalls, using pandemic models for a range of attack rates and durations. the emergence of the swine origin ph1n1 virus has led to concerns about shortfalls in our ability to provide pediatric ventilation and critical care support.	2010	20473239
longitudinal investigation of clostridium difficile shedding in piglets.	a longitudinal study of clostridium difficile colonization in piglets was performed on a conventional swine farm in ontario, canada. fecal samples were collected from 10 sows prior to their expected farrowing date, and then from all their piglets on days 2, 7, 30, 44 and 62 of life. c. difficile was isolated from 4/10 (40%) of sows prior to farrowing, 90/121 (74%) piglets on day 2, 66/117 (56%) on day 7, 45/113 (40%) on day 30, 23/101 (23%) on day 44 and 2/54 (3.7%) on day 62. there was a signif ...	2010	20708700
clinical signs and their association with herd demographics and porcine reproductive and respiratory syndrome (prrs) control strategies in prrs pcr-positive swine herds in ontario.	the purposes of this study were to describe the clinical signs observed in prrs positive herds during a porcine reproductive and respiratory syndrome (prrs) outbreak in ontario and to determine associations between these clinical signs and herd demographics and prrs control strategies. all prrs polymerase chain reaction-(pcr)-positive submissions to a diagnostic laboratory between september 1, 2004 and august 31, 2007 were identified (n = 1864). after meeting eligibility requirements and agreein ...	2010	20885840
relationship between estimated finishing-pig space allowance and in-transit loss in a retrospective survey of 3 packing plants in ontario in 2003.	the objective of this study was to determine the association between space allowance and in-transit loss of finishing pigs going to select abattoirs in ontario during summer weather conditions. the study included data from 2- or 3-tiered trailers transporting ≥ 130 pigs in june, july, and august 2003 to 3 packers that processed 76% of ontario market pigs. daily in-transit loss data were merged with packer data to determine the number of pigs on each trailer. space allowance (in square meters per ...	2010	20885841
canadian integrated program for antimicrobial resistance surveillance (cipars) farm program: results from finisher pig surveillance.	in 2006, the canadian integrated program for antimicrobial resistance surveillance (cipars) farm program was implemented in sentinel grower-finisher swine herds in québec, ontario, manitoba, saskatchewan and alberta. herds were visited 1-3 times annually. faecal samples were collected from pens of close-to-market (ctm) weight (>80 kg) pigs and antimicrobial use (amu) data were collected via questionnaires. samples were cultured for generic escherichia coli and salmonella and tested for antimicro ...	2010	21083820
antimicrobial resistance in generic escherichia coli isolates from wild small mammals living in swine farm, residential, landfill, and natural environments in southern ontario, canada.	to assess the impacts of different types of human activity on the development of resistant bacteria in the feces of wild small mammals, we compared the prevalences and patterns of antimicrobial resistance and resistance genes in generic escherichia coli and salmonella enterica isolates from fecal samples collected from wild small mammals living in four environments: swine farms, residential areas, landfills, and natural habitats. resistance to antimicrobials was observed in e. coli isolates from ...	2010	21131524
risk factors associated with escherichia coli o157:h7 in ontario beef cow-calf operations.	the aim of this study was to identify farm management factors associated with the prevalence of escherichia coli o157:h7 among cattle in ontario beef cow-calf operations. a total of 119 cow-calf operations with more than 50 cows in southern ontario were visited between june and december 2002. from each farm, 65 fresh fecal samples were collected and cultured for e. coli o157:h7. colonies of e. coli o157:h7 were isolated using immunomagnetic separation and standard microbiological techniques. fin ...	2009	19692131
parotitis in a child infected with triple-reassortant influenza a virus in canada in 2007.	swine h3n2 influenza virus designated a/ontario/1252/2007 was isolated from a child with parotitis. diagnosis was confirmed by viral isolation and serological assays. a/ontario/1252/2007 was related to h3n2 triple reassortants that emerged in swine in the united states in 1998. three of five tested household members were also seropositive for a/ontario/1252/2007.	2009	19339469
distribution of sulfonamide resistance genes in escherichia coli and salmonella isolates from swine and chickens at abattoirs in ontario and québec, canada.	sulfonamide-resistant escherichia coli and salmonella isolates from pigs and chickens in ontario and québec were screened for sul1, sul2, and sul3 by pcr. each sul gene was distributed differently across populations, with a significant difference between distribution in commensal e. coli and salmonella isolates and sul3 restricted mainly to porcine e. coli isolates.	2009	19633109
antimicrobial resistance in escherichia coli isolates from swine and wild small mammals in the proximity of swine farms and in natural environments in ontario, canada.	wild animals not normally exposed to antimicrobial agents can acquire antimicrobial agent-resistant bacteria through contact with humans and domestic animals and through the environment. in this study we assessed the frequency of antimicrobial resistance in generic escherichia coli isolates from wild small mammals (mice, voles, and shrews) and the effect of their habitat (farm or natural area) on antimicrobial resistance. additionally, we compared the types and frequency of antimicrobial resista ...	2009	19047381
using data collected for production or economic purposes to research production animal welfare: an epidemiological approach.	epidemiologists use the analyses of large data sets collected for production or economic purposes to research production nonhuman animal welfare issues in the commercial setting. this approach is particularly useful if the welfare issue is rare or hard to reproduce. however, to ensure the information is accurate, it is essential to carefully validate these data. the study used economic data to research in-transit deaths of finishing pigs. the most appropriate model to fit the distribution of the ...	2009	19319713
intensive hog farming operations and self-reported health among nearby rural residents in ottawa, canada.	in 2004, hog farming operations were introduced in the village of sarsfield in the eastern part of ottawa, canada. this study evaluates the health-related quality of life (hrqol), and the prevalence of respiratory conditions among adults and children who lived in proximity to this farm.	2009	19744310
molecular epidemiology and antimicrobial resistance of salmonella typhimurium dti04 on ontario swine farms.	this study was conducted to examine antimicrobial resistances, plasmid profiles, and pulsed-field gel electrophoresis patterns of 80 salmonella typhimurium (including var. copenhagen) dt104 strains (including dt104a and dt104b) recovered from pig and environmental fecal samples on 17 swine farms in ontario. no resistance was observed to amoxicillin/clavulanic acid, apramycin, carbadox, cephalothin, ceftriaxone, ceftiofur, cefoxitin, ciprofloxacin, nalidixic acid, trimethoprim, and tobramycin. ho ...	2008	18505209
a longitudinal study of the salmonella status on ontario swine farms within the time period 2001-2006.	in order to describe the farm-level salmonella status, 113 ontario swine farms were tested for salmonella one to five times within the time period 2001-2006. during 422 visits, 6844 fecal samples were collected and cultured for salmonella. salmonella was recovered from 437 (6.38%) of the fecal samples, and 69 (61%) of the farms had at least one positive sample over the entire period of the study. salmonella was not recovered on 11 farms of the 54 farms visited five times, nor from 7 of the 17 fa ...	2008	18681793
pig and herd level prevalence of toxoplasma gondii in ontario finisher pigs in 2001, 2003, and 2004.	the objective of this study was to estimate the apparent and true prevalence of exposure to toxoplasma gondii in ontario finisher pigs. during the study period (2001 to 2004), sera from 6048 pigs were tested with a commercial enzyme-linked immunosorbent assay (elisa); 103 farms were included 1 to 3 times in the study. true prevalence was estimated using a bayesian approach. apparent prevalence at the pig level was 1.59% [95% confidence interval (ci): 0.45, 2.99] in 2001, 0.06% (95% ci: 0.00, 0.4 ...	2008	18783018
factors associated with in-transit losses of market hogs in ontario in 2001.	in-transit losses and stage of transport when deaths occurred were determined for 4 760 213 market-weight pigs produced in 2001 by 4159 ontario producers and marketed through 117 transport companies to 33 packers located in canada (96%) and the united states. approximately 73% and 21% of producers marketed < 2000 pigs and < 500 pigs, respectively. in-transit loss was 0.017%, with 75% of producers losing < or = 5 pigs annually. approximately half of in-transit losses occurred on the truck, with 1 ...	2008	19086368
association between in-transit loss, internal trailer temperature, and distance traveled by ontario market hogs.	an observational study was conducted from july to october 2004 to determine the association between in-transit losses of swine and internal trailer temperature after controlling for loading density, trip distance, herd size, and random trip effect. a convenience sample of 3 trucking companies was used to collect temperature, relative humidity, and global positioning data for 104 trips that delivered 21,834 pigs from 371 producers to ontario abattoirs. the association between in-transit loss and ...	2008	19086369
the emergence of a new strain of porcine circovirus-2 in ontario and quebec swine and its association with severe porcine circovirus associated disease--2004-2006.	in the late fall of 2004 more severe lesions of porcine circovirus-2 associated disease (pcvad) than usual occurred during an outbreak of porcine circovirus-2 (pcv-2) infection in ontario nursery and grower/finisher pigs. the lesions were of unprecedented severity and included diffuse bronchointerstitial pneumonia, granulomatous enteritis, vasculitis, interstitial nephritis, and new lesions of splenic infarction. some affected herds had up to 50% mortality. the outbreak correlated with the sudde ...	2008	18505190
distribution of salmonella serovars and phage types on 80 ontario swine farms in 2004.	the objective of this study was to describe the distribution of salmonella spp. on ontario grower-finisher pig farms. eighty swine farms were visited from january through july 2004. on each farm, fecal samples were collected from 5 pens, 2 rectal samples and 1 pooled sample from fresh manure on the floor per pen. salmonella was isolated from 91 (11%) of the 800 rectal samples and 73 (18%) of the 397 pooled samples. overall, salmonella was recovered from 37 (46%) of the 80 farms. on each positive ...	2008	18214155
molecular characterization of hepatitis e virus detected in swine farms in the province of quebec.	swine hepatitis e virus (hev) could be a zoonotic agent for hev infection in humans. in canada, approximately 60% of 6-mo-old commercial pigs are seropositive for hev; the prevalence is higher in the provinces of quebec and ontario. a study was set up to evaluate the presence of swine hev in quebec farms and to compare the strains detected in fecal samples with human and swine hev strains reported worldwide. fecal samples were collected randomly from may 2003 to january 2004 from 70 swine farms ...	2008	18214158
a homolog of the o157 urease-encoding o island 48 is present in porcine o149:h10 enterotoxigenic escherichia coli.	the relationship of the urease operon in the highly virulent o149 porcine enterotoxigenic escherichia coli (etec) strain ro8 to a genomic island (gi) homologous to o island (oi) 48 of o157 enterohemorrhagic e. coli (ehec) strain edl933 was investigated. eighty-four of 84 o149:h10 strains were urease positive whereas 44 of 44 o149:h43 porcine etec strains were urease-negative. seventeen of 17 o149:h10 strains that were tested possessed the oi-48 homolog whereas 24 of 24 o149:h43 strains lacked th ...	2008	18316019
an investigation of the presence of escherichia coli o149:k91:f4 on pig farms in southern ontario and the use of antimicrobials and risk factors associated with the presence of this serogroup.	prevalence, causative factors, treatment, and preventative measures for o149:k91:f4 escherichia coli infection of postweaning pigs was determined by using a cross-sectional study including 70 farms in ontario. surveys were distributed and samples cultured bacteriologically, resulting in 30% of farms testing positive to e. coli 0149:k91:f4. possible causative factors, such as housing or nutrition, were not significantly different between positive and negative farms. use of injectable antibiotics ...	2008	18320976
bone weathering patterns of metatarsal v. femur and the postmortem interval in southern ontario.	twenty-five defleshed pig femora and 25 metatarsals were placed outdoors and observed over 291 days to establish: (1) bone weathering patterns for use in estimating time since death in southern ontario and (2) whether larger (femora) or smaller (metatarsals) bones provide a better indicator of time since death. pig hind limbs were observed to determine a timeline for decomposition of soft tissues during the fall and winter. ambient air temperature, humidity, precipitation, sunlight, soil ph, and ...	2008	18359589
prevalence and patterns of antimicrobial resistance of fecal escherichia coil among pigs on 47 farrow-to-finish farms with different in-feed medication policies in ontario and british columbia.	the main objectives of this study were to determine the prevalence and patterns of antimicrobial resistance in pigs on farms that medicated swine ration and those that did not. a total of 940 isolates of escherichia coli from 188 pooled fecal samples obtained from weaner and finisher pigs on 47 farrow-to-finish swine farms (34 farms used in-feed medication and 13 did not) were tested for susceptibility to 21 antimicrobials using a breakpoint concentration method. the prevalence of resistance var ...	2008	18505210
associations of antimicrobial uses with antimicrobial resistance of fecal escherichia coli from pigs on 47 farrow-to-finish farms in ontario and british columbia.	this study assessed the associations between antimicrobial use and other management practices in pigs and antimicrobial resistance in generic escherichia coli recovered from feces of weaner and finisher pigs on 39 purposefully selected farrow-to-finish farms in ontario and 8 in british columbia. antimicrobials (n = 13), most frequently penicillins and tetracycline, wer dministered to different age groups of pigs on study farms through various routes of administration. logistic regression was use ...	2008	18505211
comparison of agar dilution and e-test for antimicrobial susceptibility testing of campylobacter coil isolates recovered from 80 ontario swine farms.	the primary aim of this study was to evaluate the level of agreement of the e-test for in vitro antimicrobial susceptibility testing of campylobacter coli using the agar dilution technique, which is the approved method. a convenience sample of 80 ontario swine farms was chosen for this study; each farm was visited from january to june 2004. a total of 233 isolates of c. coli were tested for susceptibility to 10 antimicrobials by agar dilution and the e-test. performance of the tests was evaluate ...	2008	18505206
pre-clinical remote telesurgery trial of a da vinci telesurgery prototype.	the objective of this study was to perform a pre-clinical remote telesurgery trial of a da vinci telesurgery prototype on a surgical-grade virtual private network.	2008	18803341
evaluation of the risks of shedding salmonellae and other potential pathogens by therapy dogs fed raw diets in ontario and alberta.	dogs that participate in animal-assisted interventions (aais), often called 'therapy dogs', commonly interact with humans whose immune systems are not functioning optimally. the advisability of feeding raw meat (including poultry) to these animals remains a highly contentious issue, in spite of increasing evidence that raw meat is frequently contaminated with salmonella. we set out to determine if consuming raw meat influences the risk of therapy dogs shedding salmonella and other pathogens. two ...	2008	18811908
occurrence of campylobacter spp. in raw and ready-to-eat foods and in a canadian food service operation.	the occurrence of campylobacter spp. in a variety of foods from ottawa, ontario, canada, and raw milk samples from across canada was determined over a 2-year period. the samples consisted of 55 raw foods (chicken, pork, and beef), 126 raw milk samples from raw milk cheese manufacturers, and 135 ready-to-eat foods (meat products, salads, and raw milk cheeses). campylobacter jejuni was detected in 4 of the 316 samples analyzed: 1 raw beef liver sample and 3 raw chicken samples. an isolation rate o ...	2008	18939758
methicillin resistant staphylococcus aureus colonization in pigs and pig farmers.	methicillin resistant staphylococcus aureus (mrsa) colonization has recently been identified in pigs and people that work with pigs, raising concerns about the role of pigs as reservoirs of mrsa for human infection. the objectives of this study were to evaluate the prevalence of mrsa colonization in pigs and pig farmers in ontario, canada and to characterize mrsa strains. nasal and rectal swabs were collected from 285 pigs from three different age groups from 20 pig farms. nasal swabs were colle ...	2008	18023542
multilevel analysis of risk factors for salmonella shedding in ontario finishing pigs.	the objectives of this study were to identify factors associated with salmonella status at the farm, pen, and pig level; explore the nature of variation in the association between the pen-level salmonella status and pen-level covariates, and pig-level salmonella status and pig- and pen-level covariates; and to identify the relative importance of factors operating at geographical, farm, and pen level for salmonella shedding of pigs. for these purposes, samples from 799 pigs and 374 pens on 80 far ...	2008	18047752
investigation of exposure to swine influenza viruses in ontario (canada) finisher herds in 2004 and 2005.	the epidemiology of influenza in the north american swine population has changed since the emergence of a triple-reassortant h3n2 influenza virus. although seen previously in north america, the ontario swine population had likely been free of viruses of the reassortant h3n2 lineage until 2005. the objective of this study was to investigate the frequency and distribution of exposure to h1n1 and h3n2 subtypes in the ontario finisher pig population prior to and after the h3n2 outbreak that occurred ...	2008	17604859
prevalence of and risk factors for influenza in southern ontario swine herds in 2001 and 2003.	this research included 2 prevalence studies and a risk-factor investigation conducted in 2001 at 93 sites with sows only, finishers only, or both. in 2001, 1300 serum samples from sows in 65 herds and 720 serum samples from finisher pigs in 72 herds were tested for antibodies to swine influenzavirus (siv) of h1n1 subtype with an enzyme-linked immunosorbent assay (elisa). in 2003, 1140 serum samples from sows in 76 herds were tested for antibodies to siv of h3n2 subtype with a hemagglutination-in ...	2008	18214156
prevalence of actinobacillus pleuropneumoniae, actinobacillus suis, haemophilus parasuis, pasteurella multocida, and streptococcus suis in representative ontario swine herds.	tonsillar and nasal swabs were collected from weanling pigs in 50 representative ontario swine herds and tested for the presence of 5 important bacterial upper respiratory tract pathogens. all but 1 herd (2%) tested positive for streptococcus suis by polymerase chain reaction (pcr); 48% of herds were s. suis serovar 2, 1/2 positive. in all but 2 herds there was evidence of haemophilus parasuis infection. in contrast, toxigenic strains of pasteurella multocida were detected by a p. multocida--enz ...	2008	18505187
spatial clustering of swine influenza in ontario on the basis of herd-level disease status with different misclassification errors.	this approach maximizes sensitivity of serology-based monitoring systems by considering spatial clustering of herds classified as false positive by herd testing, allowing outbreaks to be detected in an early phase. the primary objective of this study was to determine whether swine herds infected with influenza viruses cluster in space, and if so, where they cluster. the secondary objective was to investigate the combining of a multivariate spatial scan statistic with herd test results to maximiz ...	2007	17531333
prevalence of campylobacter spp isolated from grower-finisher pigs in ontario.	this study aimed to establish the prevalence of campylobacter spp. in 80 ontario grower-finisher pig herds. ninety-nine percent of the isolates yielded campylobacter, c coli being the most common species detected. control of this microorganism must rely on careful food processing and storage of pork, rather than on an on-farm approach.	2007	17542372
prevalence of resistance to 11 antimicrobials among campylobacter coill isolated from pigs on 80 grower-finisher farms in ontario.	we carried out a cross-sectional study to investigate antimicrobial resistance patterns of campylobacter coli isolated from ontario grower-finisher pigs. from january to june 2004, 1200 samples were collected from 80 farms by obtaining a constant number (15) of fecal samples per farm. susceptibility of the isolates to 11 antimicrobial drugs was determined by the agar-dilution technique. the overall prevalence of resistance to 1 or more antimicrobials among the isolates was 99.2%. high levels of ...	2007	17695593
evaluation of enzyme-linked immunosorbent assay (elisa) tests and culture for determining salmonella status of a pig herd.	the purpose of this study was to evaluate salmonella elisa tests and a culture technique to determine salmonella status using samples collected from commercial herds. faecal samples from 15 finisher pigs on each of 40 swine farms were cultured for salmonella. sera from the same 600 pigs were analysed for the presence of antibodies to salmonella by means of two different elisa kits salmotype (salmotype labordiagnostik, leipzig, germany) and idexx (herdchek* salmonella; idexx laboratories, schipho ...	2007	16824251
seroprevalence of lawsonia intracellularis in different swine populations in 3 provinces in canada.	porcine proliferative enteropathy caused by lawsonia intracellularis is an important enteric disease in swine throughout the world. information regarding the distribution of this pathogen in canadian swine herds would be beneficial for the creation of control protocols. pigs from ontario, quebec, and alberta were tested by using an indirect immunofluorescence assay for antibodies to l. intracellularis. pig seroprevalence was calculated as the proportion of pigs positive from total pigs tested in ...	2007	17310623
laboratory-based vascular anastomosis training: a randomized controlled trial evaluating the effects of bench model fidelity and level of training on skill acquisition.	although there is growing evidence that practice on bench model simulators can improve the acquisition of technical skill in surgery, the degree to which these models have to approximate real-world conditions (model fidelity) to optimize learning is unclear. previous research suggests that low-fidelity models may be adequate for novice learners. the purpose of this study was to assess the effect of model fidelity and surgical expertise on the acquisition of vascular anastomosis skill.	2007	17264015
factors influencing the concentration of volatile fatty acids, ammonia, and other nutrients in stored liquid pig manure.	in order to minimize odor and manage nutrients in liquid pig manure we need to be able to predict what operational practices most influence the concentrations of volatile fatty acids (vfas), ammonium nitrogen (nh(4)(+)-n), and other nutrients present in the manure. to determine this, we collected manure from 15 pig operations in southwestern ontario in the fall of 2001 and 2002 and spring of 2002 and 2003. the manure was stored in concrete tanks at all operations. manure from finishing pigs had ...	2007	17255631
health hazard alerts. suspected tampering associated with various ham and sliced meat products. canadian food inspection agency, ottawa, ontario.		2006	17175599
porcine circovirus-2 associated disease in swine in ontario (2004 to 2005).		2006	16933552
prevalence of salmonella spp. on canadian pig farms using liquid or dry-feeding.	the objective of this study was to determine whether the shedding and antibody titre to salmonella was lower for pig herds provided liquid-feed compared to those on traditional dry rations. twenty liquid-feeding farms and 61 dry-feeding farms were selected. the amount of antibodies to salmonella in sera from 15 finisher pigs on each of 80 ontario swine farms was analyzed by means of enzyme-linked immunosorbent assay (elisa). in addition, the presence of salmonella on the 20 liquid-feeding farms ...	2006	16202460
antibiotic resistance of campylobacter jejuni and campylobacter coli isolated from hog, beef, and chicken carcass samples from provincially inspected abattoirs in ontario.	campylobacterjejuni is one of the most common causes of bacterial foodborne infection in the united states, and there are reports of resistance of campylobacter spp. to antimicrobial agents used for the treatment of gastroenteritis. the purpose of this study was to determine the antimicrobial resistance patterns of campylobacter spp. isolated from hog, beef, and chicken carcasses from provincially inspected abattoirs in ontario. the agar dilution method was performed to measure antimicrobial res ...	2006	16416896
identification of human h1n2 and human-swine reassortant h1n2 and h1n1 influenza a viruses among pigs in ontario, canada (2003 to 2005).	since 2003, three novel genotypes of h1 influenza viruses have been recovered from canadian pigs, including a wholly human h1n2 virus and human-swine reassortants. these isolates demonstrate that human-lineage h1n2 viruses are infectious for pigs and that viruses with a human pb1/swine pa/swine pb2 polymerase complex can replicate in pigs.	2006	16517910
chloramphenicol and kanamycin resistance among porcine escherichia coli in ontario.	the purpose of this study was to compare the distribution of chloramphenicol and kanamycin resistance genes across three populations of porcine escherichia coli.	2006	16720568
triple reassortant h3n2 influenza a viruses, canada, 2005.	since january 2005, h3n2 influenza viruses have been isolated from pigs and turkeys throughout canada and from a swine farmer and pigs on the same farm in ontario. these are human/classical swine/avian reassortants similar to viruses that emerged in us pigs in 1998 but with a distinct human-lineage neuraminidase gene.	2006	16836834
sow shoulder lesions: risk factors and treatment effects on an ontario farm.	the objectives of this study were to identify risk factors for the development of shoulder lesions in lactating sows and to determine if an effective, economical, and practical treatment could be designed. the study was conducted at a 300-sow farrow-to-finish swine farm in ontario between july and december 2004. sow data were recorded on either the day of or 1 d after entering the farrowing crate and before farrowing had occurred. the right and left shoulders of the sows were assigned a score be ...	2006	16908656
antimicrobial resistance and virulence genes of escherichia coli isolates from swine in ontario.	a total of 318 escherichia coli isolates obtained from diarrheic and healthy pigs in ontario from 2001 to 2003 were examined for their susceptibility to 19 antimicrobial agents. they were tested by pcr for the presence of resistance genes for tetracycline, streptomycin, sulfonamides, and apramycin and of 12 common virulence genes of porcine e. coli. antimicrobial resistance frequency among e. coli isolates from swine in ontario was moderate in comparison with other countries and was higher in is ...	2005	16269706
comparison of 2 serologic tests for the diagnosis of porcine proliferative enteropathy.	the purpose of this study was to compare results from 2 serological assays at the individual- and herd-level for porcine proliferative enteropathy diagnosis. cohen's kappa coefficient (k) was used to measure agreement. the tests tend to show better agreement when used at the herd level.	2005	16018563
an in vivo evaluation of the mycobacterial filtration efficacy of three breathing filters used in anesthesia.	the use of breathing filters (bfs) has been recommended to protect the anesthesia apparatus in proven or suspected cases of tuberculosis. some investigators have also suggested the use of bf to alleviate the need to change anesthesia breathing circuits after each case. this study evaluated the filtration efficacy of three different bfs to prevent mycobacterial contamination of breathing circuits in a model that uses a test animal.	2004	15220778
effects of porcine reproductive and respiratory syndrome vaccination in breeding-age animals.	little is known about the safety and efficacy of extra-label use of the modified live porcine reproductive-and-respiratory syndrome (prrs) virus vaccine in gestating sows. our purpose was to determine the impact of vaccination on reproductive performance in 54 herds in ontario, manitoba (canada) and the mid-western united states that were prrs-positive, prrs-negative, or concurrently affected by an outbreak of prrs when initially vaccinated. majority-vaccinated herds vaccinated > or =50% but <10 ...	2004	15068893
antibiotic resistance of salmonella isolated from hog, beef, and chicken carcass samples from provincially inspected abattoirs in ontario.	the emergence of antimicrobial-resistant salmonella organisms, especially salmonella typhimurium dt104, has been reported in many countries, including the united states and canada. the purposes of this study were to determine the antimicrobial resistance patterns of salmonella isolated from hog, beef, and chicken carcasses from provincially inspected abattoirs in ontario and to determine the agreement between the agar dilution method and the microbroth dilution method for measurement of antimicr ...	2004	15035356
field trial assessment of the efficacy of specific egg-yolk antibody product for control of postweaning e. coli diarrhea.	postweaning diarrhea caused by escherichia coli is a major cause of mortality and morbidity in many swine nurseries throughout north america. commercial products containing chicken egg-yolk antibodies specific for the control of k88+ e. coli diarrhea have been used in an attempt to prevent disease losses. the present study evaluated the use of an egg-yolk antibody product incorporated into nursery feed on two farms where k88+ e. coli diarrhea was identified as a problem. there were no difference ...	2003	15136989
relationship between group a porcine rotavirus and management practices in swine herds in ontario.	a case-control epidemiological study was conducted to determine whether an increased diagnostic rate for group a rotavirus in swine herds in ontario was associated with specific management factors. the number of new herds tested per year and the proportion of new positive herds increased between 1994 and 1997. herd size was larger and weaning age was younger in rotavirus-positive herds compared with rotavirus-negative herds. pigs raised in all-in all-out nurseries were 3.4 times more likely to h ...	2003	13677596
presentation of postweaning escherichia coli diarrhea in southern ontario, prevalence of hemolytic e. coli serogroups involved, and their antimicrobial resistance patterns.	post-weaning escherichia coli diarrhea (pwecd) in ontario was investigated using a case-control study involving 50 ontario nurseries. the clinical signs and the impact on productive parameters were determined by means of a producer survey. the hemolytic e. coli serogroups involved in pwecd (o149:k91:k88) were examined in this study. based on a polymerase chain reaction test, the hemolytic e. coli from 82% of the case herds were positive for 3 enterotoxins (sta, stb, and lt), those from 12% of th ...	2002	11989737
restriction fragment length polymorphism of porcine reproductive and respiratory syndrome viruses recovered from ontario farms, 1998-2000.	from january 1998 to july 2000, 2,456 clinical samples, including lung, tonsil, lymph node, and serum, from 760 cases submitted to the animal health laboratory, ontario, canada, were tested for porcine reproductive and respiratory syndrome viruses (prrsv) using reverse transcriptase polymerase chain reaction (rt-pcr) and rt-pcr product restriction fragment length polymorphism (rflp) analysis. a total of 516 samples from 284 cases were rt-pcr positive for the prrsv open reading frame (orf) 7 sequ ...	2002	12152819
prevalence of hepatitis e virus antibodies in canadian swine herds and identification of a novel variant of swine hepatitis e virus.	swine hepatitis e virus is a newly identified potentially zoonotic virus from pigs of particular concern for possible direct transmission to a human xenotransplant recipient by organ transplantation. in the present study, prevalence of serum antibodies to hepatitis e virus was examined in canadian swine herds. a total of 998 serum samples collected from 6-month-old healthy slaughter hogs were examined by enzyme immunoassay and western blot analysis for antibodies to the recombinant open reading ...	2001	11687465
prevalence of o1/k1- and o2/k3-reactive actinobacillus suis in healthy and diseased swine.	a cell surface antigen-typing system was devised for the swine pathogen actinobacillus suis and used to examine the prevalence of different lipopolysaccharide (o) types in healthy and diseased pigs. the strains examined in this study were isolated from a variety of locations in canada and from kansas. lipopolysaccharide preparations of 151 isolates of a. suis were characterized by immunoblotting using polyclonal antisera generated to strains so4 (o1/k1), h89-1173 (o2/k3), and vsb 3714, a rough s ...	2000	11015398
h4n6 influenza virus isolated from pigs in ontario.		2000	11143928
h3n2 influenza a virus recovered from a neonatal pig in ontario--1997.		1999	10646069
a descriptive study of the frequency and characteristics of proliferative enteropathy in swine in ontario by analyzing routine animal health surveillance data.	routine surveillance data, collected on pathology submissions at the animal health laboratory in guelph between 1992 and 1997, were analyzed to determine demographic, clinical, and pathologic characteristics of cases of proliferative enteropathy and the frequency of this condition relative to other infectious enteric diseases in swine in ontario. the most commonly reported disease was escherichia coli enteritis (average cases/year = 70.0). among infectious enteropathies that occur typically in n ...	1999	10572667
antimicrobial drug use and related management practices among ontario swine producers.	a mail survey of swine producers in ontario was undertaken during 1991 to describe the types, frequency, and motives for antimicrobial use. two hundred operations that marketed fewer than 350 hogs per year, and 800 that marketed more than 350 per year were sent questionnaires, 63% of which were completed and returned. most operations (86%) added antimicrobials to starter (weanling pig) rations, while fewer (29%) added these drugs to finisher pig rations. the most commonly used antimicrobials wer ...	1998	10051955
a three year experience with the toronto stentless porcine valve.	in the three year period from march 1994, 112 toronto stentless porcine valves (spv tm) were implanted in the western infirmary, glasgow. there were 55 males and 57 females aged between 45 and 86 years (mean 70.9 +/- 7.2 yrs). the mean preoperative aortic gradient was 89 +/- 27 mmhg. fifty-three patients (47%) had an isolated first time aortic valve replacement. myocardial revascularisation was carried out in 51 patients (46%) with a mean of 1.7 +/- 0.9 coronary bypass grafts per patient. six pa ...	1998	9660911
associations among antimicrobial drug treatments and antimicrobial resistance of fecal escherichia coli of swine on 34 farrow-to-finish farms in ontario, canada.	logistic regression was used to model associations between antimicrobial treatment and resistance among fecal escherichia coli of finisher pigs at the farm level. four sets of potential risk factors representing different levels of refinement of antimicrobial use on farms were modelled on resistance to antimicrobials. final models for each antimicrobial were constructed from treatment and management variables significant on initial screening, and corrections for overdispersion were made. in gene ...	1998	9618742
retrospective study of toxic metal analyses requested at a veterinary diagnostic toxicology laboratory in ontario (1990-1995).	during the 5-year period from january 1, 1990, to december 31, 1995, 887 diagnoses of metal toxicosis in domestic animals and wild birds were documented at the veterinary laboratory services branch of the ontario ministry of agriculture, food and rural affairs. most of these cases involved cattle, sheep, and birds. lead toxicosis was diagnosed in 399 cases, copper toxicosis in 387, zinc toxicosis in 49, mercury toxicosis in 44, iron toxicosis in 4, and selenium in 4 cases. trends in species affe ...	1998	9442951
prevalences of resistance to seven antimicrobials among fecal escherichia coli of swine on thirty-four farrow-to-finish farms in ontario, canada.	fecal specimens were composited and a hydrophobic-grid membrane-filter method was used to measure antimicrobial resistance to ampicillin 16 micrograms/ml, carbadox 30 micrograms/ml, gentamicin 4 mu/ml, nitrofurantoin 32 micrograms/ml, spectinomycin 16 micrograms/ml, sulfisoxazole 32 micrograms/ml and tetracycline 8 micrograms/ml among 8119 escherichia coli isolates from 68 fecal samples collected on 34 farrow-to-finish swine farms marketing over 500 hogs/yr. the overall prevalences of resistance ...	1998	9618741
individual and group antimicrobial usage rates on 34 farrow-to-finish swine farms in ontario, canada.	antimicrobial drug-use was assessed on 34 farrow-to-finish operations that marketed at least 500 hogs/yr. these operations either did not use any antimicrobials or used narrow-spectrum or broad-spectrum antimicrobials in rations of post-weaning pigs. total antimicrobial use was measured for two months after obtaining inventories and records of all antimicrobials used. the collection of empty medication bottles and inventories of drugs on hand was convenient for producers and useful for estimatin ...	1998	9618740
patterns of crossfostering and piglet mortality on commercial u.s. and canadian swine farms.	a data base of 300 farms using computerized records was used to examine the extent and timing of crossfostering being practiced in commercial herds in the midwestern u.s. and canada in 1994-1995. crossfostering was used on 98% of farms. across all farms, the mean percent of piglets crossfostered was 8.6%. farms varied greatly in the age at which they moved piglets. the 20 farms that moved piglets the earliest after birth were classified as early-move farms and the 20 that moved the oldest piglet ...	1998	9500166
outbreak of trichinosis in ontario secondary to the ingestion of wild boar meat.	we report an outbreak of trichinosis from the consumption of locally processed, cold smoked wild boar meat of a domestically reared animal from a farm in dufferin county, ontario. between january and march 1993, 24 cases of trichinosis were identified and of these, 21 patients were symptomatic. the most common symptoms were myalgia (75%), weakness (75%), fever (71%) and periorbital edema (67%). eosinophilia and elevated creatine phosphokinase levels were noted in 86% and 89% of patients respecti ...	1997	9094806
status of trichinella spiralis in domestic swine and wild boar in canada.	evidence of the status of trichinellosis in canada's national swine herd is provided from data acquired through national surveillance programs and from a prevalence study of trichinella in wild boar and domestic swine. more than 500,000 swine tested at abattoirs in ongoing animal health surveys since 1980 and 2 national swine serological surveys (1985 and 1990) showed no evidence of trichinella infection, except for 3 occurrences in a small infected zone in nova scotia. the prevalence study of d ...	1997	9342448
antigenic comparison of canadian and us isolates of porcine reproductive and respiratory syndrome virus using monoclonal antibodies to the nucleocapsid protein.	fifteen canadian field isolates of porcine reproductive and respiratory syndrome (prrs) virus from quebec and ontario were compared with 5 us prrs virus (prrsv) isolates and with the european lelystad isolate using monoclonal antibodies (mabs) sdow17, ep147, and vo17 directed to the 15-kda nucleocapsid protein of prrsv. all canadian and us isolates tested by indirect immunofluorescence were recognized by the 3 mabs, and individual titers of mabs towards canadian and us prrsv isolates were simila ...	1995	8521358
assessment of seropositivity to porcine reproductive and respiratory syndrome (prrs) virus in swine herds in ontario--1978 to 1982.		1995	8748450
isolation of a distinct serotype of porcine reproductive and respiratory syndrome (prrs) virus in ontario.		1995	8748451