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Abstract

Objective—To describe shiga-toxigenic Escherichia coli O157:H7 (STEC O157:H7) fecal shedding prevalence, seasonal fecal shedding patterns, and site-specific prevalence from the oral cavity, skin, and feces of dairy cattle.

Design—Cross-sectional study.

Animals—Adult dairy cattle from 13 herds in Louisiana.

Procedure—Samples were cultured for STEC O157 by use of sensitive and specific techniques, including selective broth enrichment, immunomagnetic separation, monoclonal antibody-based O:H enzyme immunoassay serotyping, and polymerase chain reaction virulence gene characterization. Point estimates and 95% confidence intervals were calculated for fecal shedding prevalence as well as site-specific prevalence from the oral cavity, skin, and feces. Logistic regression was used to assess seasonal variation and differences at various stages of lactation with respect to fecal shedding of STEC O157 in cattle sampled longitudinally.

Results—Summer prevalence in herds (n = 13) was 38.5%, with a cow-level prevalence of 6.5%. Among positive herds, prevalence ranged from 3% to 34.6%. Samples from 3 of 5 herds sampled quarterly over 1 year yielded positive results for STEC O157. In herds with STEC O157, an increase in cow-level prevalence was detected during spring (13.3%) and summer (10.5%), compared with values for fall and winter. Site-specific prevalences of STEC O157:H7 from oral cavity, skin, and fecal samples were 0%, 0.7%, and 25.2%, respectively.

Conclusions and Clinical Relevance—Our data indicated that STEC O157:H7 was commonly isolated from dairy cows in Louisiana, seasonally shed, and isolated from the skin surface but not the oral cavity of cows. (J Am Vet Med Assoc 2004;224:1151–1158)

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in Journal of the American Veterinary Medical Association

Contact with animals in public venues such as fairs and petting zoos has important benefits including education concerning animals and animal husbandry, encouraging compassion for animals, and entertainment. However, contact can also lead to transmission of zoonotic disease. During 1991 to 2005, 55 outbreaks associated with animals in public settings were reported. 1 Despite national recommendations aimed at preventing disease associated with animals in public settings, 2 outbreaks continue to occur. 1

Few data are available regarding behaviors among visitors to petting zoos that may increase their risk of acquiring disease. Outbreak investigations have identified risk factors such

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether cattle testing positive for Mycobacterium avium subsp paratuberculosisas determined by microbial culture of feces or antibody ELISA were more likely to have false-positive responses on the caudal fold tuberculin (CFT) test or interferon-γ (IFN-γ) assay for Mycobacterium bovis than cattle testing negative for M paratuberculosis.

Animals—1,043 cattle from 10 herds in Michigan.

Procedure—Feces and blood samples for plasma were collected from cattle ≥ 24 months old on the day the CFT test was read. Fecal samples were submitted for microbial culture for M paratuberculosis. Plasma samples were tested for antibody against M paratuberculosis, and IFN-γ after stimulation with purified protein derivative tuberculin from M bovis or M avium.

Results—Of 1,043 cattle, 180 (17.3%) had positive CFT test results (suspects) and 8 (0.8%) had positive IFN-γ assay results after stimulation with purified protein derivative tuberculin from M bovis. Forty-five (4.3%) and 115 (11.0%) cattle tested positive for M paratuberculosis as determined by microbial culture of feces and antibody ELISA, respectively. Cattle with positive responses for M paratuberculosis appeared to have an increased likelihood of false-positive results on the CFT test, although this association was not significant.

Conclusions and Clinical Relevance—No significant association was detected among cattle testing positive for M paratuberculosis as determined by microbial culture of feces and antibody ELISA and positive CFT test and IFN-γ assay results for M bovis. (J Am Vet Med Assoc 2005;226:429–435)

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To estimate Brucella canis seropositivity rates for purebred dogs being bred by noncommercial breeders, describe epidemiological findings in infected commercial dog-production facilities, and characterize B canis infection in pet dogs and the risk to human health.

DESIGN Retrospective descriptive study.

SAMPLE 2,799 canine specimens submitted to the Michigan State University Veterinary Diagnostic Laboratory for B canis testing and records of B canis reports provided to the Michigan Department of Agriculture and Rural Development from 2007 through 2016.

PROCEDURES Results of B canis laboratory tests and epidemiological findings for reported cases of B canis were reviewed and summarized. Federal and state public health officials were interviewed regarding human B canis infection. State veterinarians were interviewed regarding canine brucellosis reporting and control procedures.

RESULTS Estimated B canis seropositivity was 0.4% among purebred Michigan dogs owned by noncommercial breeders. Infection was confirmed in dogs from 17 commercial dog-production facilities, 3 shelters, and 1 rescue agency. Estimated infection prevalence in production facilities ranged from 2 of 22 (9%) to 5 of 6 (83%). Transfer of infected dogs involved 22 Michigan counties and 11 states. Seven of 20 privately owned infected dogs had diskospondylitis; I also had uveitis. Fifty-three veterinary hospital or diagnostic laboratory personnel had inadvertent exposure to the pathogen. Brucella canis was isolated from 1 commercial production facility owner.

CONCLUSIONS AND CLINICAL RELEVANCE B canis was uncommon in purebred dogs being bred by noncommercial breeders but endemic in Michigan commercial facilities producing dogs destined to become household pets. Infected pet dogs caused human B canis exposure, and several pet dogs had debilitating disease not associated with the reproductive system.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate knowledge, attitudes, and management practices involving antimicrobial use among Tennessee beef producers.

Design—Mail survey.

Sample Population—A population-based, stratified random sample of 3,000 beef producers across the state.

Procedures—Questionnaires were mailed to beef producers. Questions focused on producer practices related to education, biosecurity, veterinary use, and the purchase and use of antimicrobials. Operation types were categorized as either cow-calf only or multiple operation type (MOT). Associations between various factors and antimicrobial use were evaluated by use of multivariable logistic regression, with the outcome variable being any antimicrobial use (injectable or by mouth) in the past year.

Results—Of 3,000 questionnaires mailed, 1,042 (34.7%) were returned. A significantly higher proportion of producers with MOTs reported giving antimicrobials by mouth or by injection than did producers with cow-calf only operations. In addition, higher proportions of producers with MOTs than producers with cow-calf only operations reported treating with macrolides, florfenicol, ceftiofur, and aminoglycosides. In the multivariable analysis, herd size >50 cattle, participation in Beef Quality Assurance or master beef producer certification programs, quarantining of newly purchased animals, use of written instructions for treating disease, and observation of withdrawal times were associated with a higher likelihood of antimicrobial use.

Conclusions and Clinical Relevance—Results suggested that producers who engaged in more progressive farming practices were also more likely to use antimicrobials. Incorporating training on judicious antimicrobial use into educational programs would likely increase awareness of best management practices regarding antimicrobial use.

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in Journal of the American Veterinary Medical Association

Abstract

In collaboration with the American College of Veterinary Pathologists

Open access
in Journal of the American Veterinary Medical Association