Quantifying antimicrobial use on Canadian dairy farms using garbage can audits.

Antimicrobial resistance in pathogenic bacteria is one of the preeminent concerns for the future of global health. There is a dose-dependent relationship between antimicrobial use (AMU) and the prevalence of antimicrobial-resistant pathogens. As most AMU in Canada is related to animal agriculture, there is a need to reduce overall AMU, which could be accomplished through surveillance of AMU in animal agriculture, including the dairy industry. The objective of this study was to quantify AMU on dairy farms across Canada. This study had two parts: a description of data collected in 2019-2020, and a meta-analysis comparing this data to previous estimates of AMU in the Canadian dairy industry. The first included a garbage can audit (GCA) on 107 farms in four Canadian provinces (British Columbia, Alberta, Ontario, and Nova Scotia) in 2020; AMU data were converted to the dose-based metrics of defined course doses (DCD) and defined daily doses (DDD). Mixed-effect linear models were fit to determine the relationship between province and use of different classes of antimicrobials. On average, for every 100 animals on the farm, 117 DCD of antimicrobials were administered per year (IQR: 55, 158). These treatments amounted to 623 DDD / 100 animal-yr (IQR: 302, 677 DDD/100 animal-years). Penicillins were the most used class of antimicrobials, followed by first-and third-generation cephalosporins. Farms in Ontario used more third-generation cephalosporins than other provinces. The second part of this study compared AMU in 2020 to previously reported Canadian studies through a meta-analysis. A GCA was conducted in 2007-2008 in Alberta, Ontario, Québec, and the Maritime provinces (Prince Edward Island, New Brunswick and Nova Scotia); another GCA was conducted in Québec in 2018. Overall, AMU was lower in 2018-2020 than in 2007-2008, with the exception of third-generation cephalosporin use, which increased.

Canadian Collaboration to Identify a Minimum Dataset for Antimicrobial Use Surveillance for Policy and Intervention Development across Food Animal Sectors.

Surveillance of antimicrobial use (AMU) and antimicrobial resistance (AMR) is a core component of the 2017 Pan-Canadian Framework for Action. There are existing AMU and AMR surveillance systems in Canada, but some stakeholders are interested in developing their own AMU monitoring/surveillance systems. It was recognized that the establishment of core (minimum) AMU data elements, as is necessary for policy or intervention development, would inform the development of practical and sustainable AMU surveillance capacity across food animal sectors in Canada. The Canadian Animal Health Surveillance System (CAHSS) AMU Network was established as a multisectoral working group to explore the possibility of harmonizing data inputs and outputs. There was a consensus that a minimum AMU dataset for AMU surveillance (MDS-AMU-surv) should be developed to guide interested parties in initiating AMU data collection. This multisectoral collaboration is an example of how consultative consensus building across relevant sectors can contribute to the development of harmonized approaches to AMU data collection and reporting and ultimately improve AMU stewardship. The MDS-AMU-surv could be used as a starting point for the progressive development or strengthening of AMU surveillance programs, and the collaborative work could serve as a model for addressing AMR and other shared threats at the human-animal-environment interface.

Informing Stewardship Measures in Canadian Food Animal Species through Integrated Reporting of Antimicrobial Use and Antimicrobial Resistance Surveillance Data-Part II, Application.

Using the methodology developed for integrated analysis and reporting of antimicrobial use (AMU) and antimicrobial resistance (AMR) data, farm-level surveillance data were synthesized and integrated to assess trends and explore potential AMU and AMR associations. Data from broiler chicken flocks (n = 656), grower-finisher pig herds (n = 462) and turkey flocks (n = 339) surveyed by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) at the farm-level (2015-2019) were used. The analyses showed a reduction in mean flock/herd level number of defined daily doses using Canadian standards (nDDDvetCA) adjusted for kg animal biomass that coincided with the decline in % resistance in the three species. This was noted in most AMU-AMR pairs studied except for ciprofloxacin resistant Campylobacter where resistance continued to be detected (moderate to high levels) despite limited fluoroquinolone use. Noteworthy was the significantly negative association between the nDDDvetCA/kg animal biomass and susceptible Escherichia coli (multispecies data), an early indication that AMU stewardship actions are having an impact. However, an increase in the reporting of diseases in recent years was observed. This study highlighted the value of collecting high-resolution AMU surveillance data with animal health context at the farm-level to understand AMR trends, enable data integration and measure the impact of AMU stewardship actions.

Informing Stewardship Measures in Canadian Food Animal Species through Integrated Reporting of Antimicrobial Use and Antimicrobial Resistance Surveillance Data-Part I, Methodology Development.

This study explores methodologies for the data integration of antimicrobial use (AMU) and antimicrobial resistance (AMR) results within and across three food animal species, surveyed at the farm-level by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). The approach builds upon existing CIPARS methodology and principles from other AMU and AMR surveillance systems. Species level data integration involved: (1) standard CIPARS descriptive and temporal analysis of AMU/AMR, (2) synthesis of results, (3) selection of AMU and AMR outcomes for integration, (4) selection of candidate AMU indicators to enable comparisons of AMU levels between species and simultaneous assessment of AMU and AMR trends, (5) exploration of analytic options for studying associations between AMU and AMR, and (6) interpretation and visualization. The multi-species integration was also completed using the above approach. In addition, summarized reporting of internationally-recognized indicators of AMR (i.e., AMR adjusted for animal biomass) and AMU (mg/population correction unit, mg/kg animal biomass) is explored. It is envisaged that this approach for species and multi-species AMU-AMR data integration will be applied to the annual CIPARS farm-level data and progressively developed over time to inform AMU-AMR integrated surveillance best practices for further enhancement of AMU stewardship actions.

Antimicrobial resistance and recovery of Salmonella, Campylobacter, and Escherichia coli from chicken egg layer flocks in Canadian sentinel surveillance sites using 2 types of sample matrices.

Eggs are important to the diet of Canadians. This product is one of the supply-managed commodities in Canada, but unlike other commodities, where food safety risks are extensively explored and reported, information on the prevalence of enteric organisms (e.g., Salmonella, Campylobacter) and antimicrobial resistance (AMR) in layers in Canada are limited. This study was conducted to determine the prevalence of select bacteria and the associated AMR patterns in layer flocks using 2 sample matrices. Farms were located within FoodNet Canada and the Canadian Integrated Program for Antimicrobial Resistance Surveillance sentinel sites (SS). Fecal samples (Ontario: ONSS1a, ONSS1b) and environmental sponge swabs (British Columbia: BCSS2a) were collected. Salmonella prevalence was 29% and 8% in ONSS1a and ONSS1b, respectively, and 7% in BCSS2a. S. Kentucky and S. Livingstone were the most frequently isolated serovars and no S. Enteritidis was detected. Campylobacter was not detected in the BC sponge swabs but was isolated from 89% and 53% of Ontario fecal samples (ONSS1a and ONSS1b, respectively). Seven C. jejuni from Ontario were ciprofloxacin-resistant. Escherichia coli prevalence was high in both sample types (98%). Overall, tetracycline resistance among E. coli ranged from 26% to 69%. Resistance to ceftiofur (n = 2 isolates) and gentamicin (n = 2) was relatively low. There were diverse resistance patterns (excludes susceptible isolates) observed among E. coli in Ontario (10 patterns) and British Columbia (14 patterns). This study revealed that fecal samples are more informative for farm-level monitoring of pathogen and AMR prevalence. Without further validation, sponge swabs are limited in their utility for Campylobacter detection and thus, for public health surveillance.

Les oeufs sont importants pour l'alimentation des Canadiens. Ce produit est l'un des produits soumis à la gestion de l'offre au Canada, mais contrairement à d'autres produits, où les risques pour la salubrité des aliments sont largement étudiés et signalés, des informations sur la prévalence des organismes entériques (p. ex. Salmonella, Campylobacter) et la résistance aux antimicrobiens (RAM) chez les pondeuses au Canada sont limitées. Cette étude a été menée pour déterminer la prévalence de certaines bactéries et les patrons de résistance aux antimicrobiens associés dans les troupeaux de pondeuses en utilisant deux matrices d'échantillons. Les fermes étaient situées au sein de FoodNet Canada et des sites sentinelles (SS) du Programme intégré canadien de surveillance de la résistance aux antimicrobiens. Des échantillons de matières fécales (Ontario : ONSS1a, ONSS1b) et des éponges environnementales (Colombie-Britannique : BCSS2a) ont été prélevés. La prévalence de Salmonella était de 29 % et 8 % pour ONSS1a et ONSS1b, respectivement, et de 7 % pour BCSS2a. Salmonella Kentucky et S. Livingstone étaient les sérotypes les plus fréquemment isolés et aucun S. Enteritidis n'a été détecté. Campylobacter n'a pas été détecté dans les éponges de la Colombie-Britannique, mais a été isolé de 89 % et 53 % des échantillons de matières fécales de l'Ontario (ONSS1a et ONSS1b, respectivement). Sept C. jejuni de l'Ontario étaient résistants à la ciprofloxacine. La prévalence d'Escherichia coli était élevée dans les deux types d'échantillons (98 %). Dans l'ensemble, la résistance à la tétracycline chez E. coli variait de 26 % à 69 %. La résistance au ceftiofur (n = 2 isolats) et à la gentamicine (n = 2) était relativement faible. Divers profils de résistance (à l'exclusion des isolats sensibles) ont été observés chez E. coli en Ontario (10 profils) et en Colombie-Britannique (14 profils). Cette étude a révélé que les échantillons fécaux sont plus informatifs pour la surveillance au niveau de la ferme de la prévalence des agents pathogènes et de la résistance aux antimicrobiens. Sans validation supplémentaire, les éponge sont limitées dans leur utilité pour la détection de Campylobacter et donc pour la surveillance en santé publique.(Traduit par Docteur Serge Messier).

Antimicrobial Use Indices-The Value of Reporting Antimicrobial Use in Multiple Ways Using Data From Canadian Broiler Chicken and Turkey Farms.

We have previously described the importance of using multiple indicators for reporting national farm-level antimicrobial use (AMU) information, but the distribution of flock-level AMU and how these indicators relate to each other has not yet been fully explored. Using farm-level surveillance data (2013-2019), for broiler chickens (n = 947 flocks) and turkeys (n = 427), this study aims to (1) characterize flock-level AMU and identify high users, (2) identify appropriate AMU indicators and biomass denominator [population correction unit (PCU) vs. kg weight at pre-slaughter], and (3) make recommendations on the application to veterinarian-producer and national-level reporting. Diverse AMU patterns were identified in broiler chickens (156 patterns) and turkeys (68 patterns); of these, bacitracin, reported by 25% of broiler chicken and 19% of turkey producers, was the most frequently occurring pattern. Depending on the indicator chosen, variations in reported quantity of use, temporal trends and relative ranking of the antimicrobials changed. Quantitative AMU analysis yielded the following results for broiler chickens: mean 134 mg/PCU; 507 number (n) of Canadian (CA) defined daily doses (DDDvet) per 1,000 chicken-days and 18 nDDDvetCA/PCU. Analysis in turkey flocks yielded the following: mean 64 mg/PCU, 99 nDDDvetCA/1,000 turkey-days at risk and 9 nDDDvetCA/PCU. Flocks were categorized based on the percentiles of the mg/PCU distribution: "medium" to "low" users (≤75th percentile) and "high" users (>75th percentile). The odds of being a high user in both broiler chickens and turkeys were significantly increased: if water medications were used, and if trimethoprim-sulfonamides, bacitracins, and tetracyclines were used. Pairwise correlation analysis showed moderate correlation between mg/PCU and the nDDDvetCA/1,000 animal days at risk and between mg/PCU and nDDDvetCA/PCU. Significantly high correlation between nDDDvetCA/1,000 animal days at risk and nDDDvetCA/PCU was observed, suggestive that either of these could be used for routine monitoring of trends in AMU. One source of discrepancy between the indicators was the antimicrobial. Understanding the choice of parameter input and effects on reporting trends in AMU will inform surveillance reporting best practices to help industry understand the impacts of their AMU reduction strategies and to best communicate the information to veterinarians, their producers, and other stakeholders.

Experiences, attitudes, and perceptions of accredited advisors towards a voluntary producer training program for Canadian Quality Milk.

This study was conducted to understand the experiences, attitudes, and perceptions of advisors towards the voluntary producer training program offered in Ontario prior to the first Canadian Quality Milk validation. A survey was used to gather advisor opinions and was sent by e-mail to all advisors listed on the Dairy Farmers of Ontario (DFO) website. ANOVA and Chi-Square analyses were utilized to identify significant differences among respondent groups (veterinarian, non-veterinarian, and unidentified), linear regression was used to evaluate associations with the number of producers an advisor trained, and logistic regression was performed to evaluate associations with advisor opinions. Advisors who trained more producers were more likely to provide both classroom and on-farm sessions, train producers with greater consistency in audit results, and remain in communication with producers they had trained. Advisor-suggested improvements for similar programs in the future were increased compensation, more use of interactive learning, and re-structured advisor training.

Expériences, attitudes, et perceptions de conseillers accrédités envers un programme de formation volontaire des producteurs pour Lait canadien de qualité. La présente étude a été menée pour comprendre les expériences, attitudes et perceptions des conseillers envers le programme volontaire de formation offert en Ontario avant la première validation de Lait canadien de qualité. Un sondage a été utilisé pour récolter les opinions des conseillers et fut acheminé par courriel à tous les conseillers listés sur le site web des Producteurs de lait de l'Ontario (DFO). Des analyses ANOVA et Chi-carré ont été utilisées pour identifier les différences significatives parmi les groupes de répondants (vétérinaires, non-vétérinaires, et non-identifiés), une régression linéaire a été utilisée pour évaluer les associations avec le nombre de producteurs et de conseillers formés, et une régression logistique fut effectuée pour évaluer les associations avec les opinions des conseillers. Les conseillers qui ont formé plus de producteurs étaient plus susceptibles à fournir des sessions de formation en classe et à la ferme, de former les producteurs avec une plus grande constance dans les résultats d'audits, et de demeurer en communication avec les producteurs qu'ils avaient formés. Des améliorations suggérées par les conseillers pour des programmes similaires futurs étaient d'augmenter le montant des compensations, une plus grande utilisation d'apprentissage interactif, et une restructuration de la formation des conseillers.(Traduit par Dr Serge Messier).

Developing Canadian Defined Daily Doses for Animals: A Metric to Quantify Antimicrobial Use.

Antimicrobial use surveillance data need to be analyzed and reported in a standardized and harmonized way. In veterinary medicine, one approach is to use defined daily doses (DDD) for animals. DDD for animals are technical standards used in various measures or metrics that quantify antimicrobial use. The European Medicines Agency published principles for assigning DDDvet values based on information on dosing obtained from nine European countries. For measuring antimicrobial use in livestock within Canada, DDDs for animals reflective of Canadian veterinary antimicrobial use (DDDvetCAs) were needed. Our objectives were (1) to describe the development of DDDvetCA standards for pigs and poultry (broiler chickens and turkeys) for authorized and compounded antimicrobial active ingredients used in Canada, including those used extra-label; and (2) to compare the DDDvetCAs with EMA's DDDvets, where possible. Species-specific DDDvetCAs were assigned based on the average of unique antimicrobial daily doses obtained from product information, stratified by route of administration and age indication (where applicable). The feed, water and bolus DDDvetCAs were compared to oral DDDvets, and injectable DDDvetCAs to parenteral DDDvets, that matched by antimicrobial active ingredient. Seventy-five DDDvetCAs were assigned for pigs; 51 for poultry. Seventeen injectable DDDvetCAs could be compared to 14 EMA's parenteral DDDvets and 53 feed, water, and bolus DDDvetCAs could be compared to 40 oral DDDvets. Feed and water DDDvetCAs were generally lower than EMA's oral DDDvets, although differences in methodology between Canada and Europe make comparisons challenging. The assignment of DDDvetCAs was a resource intensive and iterative process. EMA's published principles for assigning DDDvets were an invaluable source of information. The use of DDDvetCAs will reflect exposure of Canadian animals to antimicrobials, be useful for evaluating associations between use and resistance within Canada and provide information for risk assessment and stewardship policies. However, when reporting antimicrobial use data internationally, using the same DDD standards as other reporting countries will facilitate between country comparisons, although differences in which antimicrobial active ingredients are licensed between countries may create challenges. Future steps include assigning DDDvetCAs for other food animal species, such as cattle, veal, and farmed fish.

Antimicrobial Use and Antimicrobial Resistance Indicators-Integration of Farm-Level Surveillance Data From Broiler Chickens and Turkeys in British Columbia, Canada.

Using data from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS), we aimed to describe trends in antimicrobial use (AMU) in broiler chickens and turkeys, to compare AMU across species, to compare with trends in antimicrobial resistance (AMR), and to assess the effects of various AMU/AMR units of measurement (metrics and indicators) on data integration. Data on AMU and AMR in enteric bacteria, collected from 2013 to 2017 from broiler chickens (n = 143 flocks) and turkeys (n = 145) were used. In broiler chickens, the total AMU in milligrams/population correction unit (mg/PCUBr) decreased by 6%, the number (n) of defined daily doses for animals using Canadian standards (nDDDvetCA) per 1,000 broiler chicken-days decreased by 12%, and nDDDvetCA/PCU decreased by 6%. In turkeys, the mg/PCUTk decreased by 1%, whereas the nDDDvetCA/1,000 turkey-days and the nDDDvetCA/PCU increased by 1 and 5%, respectively. The types of antimicrobial classes used in both species were similar. Using the frequency of flocks reporting use (i.e., number of flocks reporting use/number of flocks participating) as a measurement, the use of certain antimicrobials changed over time (e.g., Broilers, decreased cephalosporin use, virginiamycin use, emerging use of lincomycin-spectinomycin, and avilamycin; Turkeys: increased trimethoprim-sulfonamides and macrolide use). The trends in resistance to specific antimicrobials paralleled the frequency and quantity of use (e.g., ceftriaxone use decreased-ceftriaxone resistance decreased, and gentamicin use increased-gentamicin resistance increased) in some situations, but not others (decreased fluoroquinolone use-increased ciprofloxacin resistance). AMR data were summarized using the AMR indicator index (AMR Ix). The most notable AMR Ix trend was the decrease in ceftriaxone AMR Ix among Escherichia coli (0.19 to 0.07); indicative of the success of the poultry industry action to eliminate the preventive use of third generation cephalosporins. Other trends observed were the increase in ciprofloxacin AMR Ix among Campylobacter from 0.23 to 0.41 and gentamicin AMR Ix among E. coli from 0.11 to 0.22, suggestive of the persistence/emergence of resistance related to previous and current AMU not captured in our surveillance timeframe. These data highlight the necessity of multiple AMU and AMR indicators for monitoring the impact of stewardship activities and interventions.

Changes in antimicrobial resistance levels among Escherichia coli, Salmonella, and Campylobacter in Ontario broiler chickens between 2003 and 2015.

Poultry has been identified as a reservoir of foodborne enteric pathogens and antimicrobial resistant bacteria. The objective of this study was to describe and compare antimicrobial resistant isolates from an Ontario broiler chicken farm-level baseline project (2003 to 2004) to the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) Ontario abattoir and retail surveillance data from 2003, and to the most recent (2015) CIPARS Ontario chicken surveillance data in order to assess the impact of an industry-wide policy change in antimicrobial use. Ceftiofur resistance (TIO-R) prevalence in Salmonella decreased by 7% on farm between 2003 and 2004 and 2015. During the same timeframe, TIO-R E. coli prevalence decreased significantly by 16%, 11%, and 8% in farm, abattoir, and retail samples, respectively. Gentamicin resistant (GEN-R) E. coli, however, increased by 10% in farm and 15% in retail-derived isolates, and trimethoprim-sulfamethoxazole resistant (TMSm-R) E. coli increased significantly by 20%, 18%, and 5% in farm, abattoir, and retail isolates, respectively. Similarly, ciprofloxacin-resistant (CIP-R) Campylobacter spp. significantly increased in retail isolates by 11% and increased in farm (33%) and abattoir isolates (7%). The decrease in TIO-R Salmonella/E. coli in recent years is consistent with the timing of an industry-led intervention eliminating the preventive use of ceftiofur, a third generation cephalosporin and class of antimicrobials deemed critically important to human medicine. The rise in GEN-R and TMSm-R prevalence is indicative of recent shifts in antimicrobial use. Our study highlights the importance of integrated surveillance in detecting emerging trends and determining the efficacy of interventions to improve food safety.

La volaille a été identifiée comme étant un réservoir d'agents pathogènes entériques d'origine alimentaire et de bactéries résistantes aux antimicrobiens. L'objectif de la présente étude était de décrire et comparer des isolats résistants aux antimicrobiens provenant d'une ferme ontarienne de poulets à griller obtenus dans le cadre d'un projet de base (2003 à 2004) aux données de surveillance de 2003 du Programme intégré canadien de surveillance de la résistance aux antimicrobiens (PICRA) d'abattoir et de ventes au détail en Ontario, et aux plus récentes données de surveillance (2015) du PICRA Ontario pour la volaille afin d'évaluer l'impact d'un changement à l'ensemble de l'industrie dans l'utilisation des antimicrobiens. La prévalence de la résistance au cefiofur (TIO-R) de Salmonella a diminué de 7 % sur la ferme entre 2003 à 2004 et 2015. Durant ce même intervalle de temps, la prévalence de TIO-R de E. coli diminua de manière significative de 16 %, 11 %, et 8 % dans les échantillons provenant de la ferme, de l'abattoir et de la vente au détail, respectivement. Toutefois, les E. coli résistant à la gentamicine (GEN-R) ont augmenté de 10 % et 15 % dans les échantillons pris à la ferme et de la vente au détail, respectivement. Les E. coli résistants au trimethoprime-sulfaméthoxazole (TMSm-R) ont augmenté de manière significative par 20 %, 18 %, et 5 % dans les isolats de la ferme, de l'abattoir et de la vente au détail, respectivement. Les isolats de Campylobacter spp. résistants au ciprofloxacin (CIP-R) augmentèrent de manière significative dans les échantillons de vente au détail (11 %), ceux de la ferme (33 %) ainsi que ceux de l'abattoir (7 %). La diminution de la TIO-R chez Salmonella/E. coli au cours des dernières années concorde avec une intervention menée par l'industrie d'éliminer l'utilisation en prévention du ceftiofur, une céphalosporine de troisième génération qui est une classe d'antimicrobiens considérée d'importance critique en médecine humaine. L'augmentation de la prévalence de GEN-R et de TMSm-R est indicative d'un changement récent dans l'utilisation des antimicrobiens. Notre étude fait ressortir l'importance d'un programme intégré de surveillance pour détecter les tendances émergentes et déterminer l'efficacité des interventions pour améliorer la salubrité alimentaire.(Traduit par Docteur Serge Messier).

Antimicrobial use surveillance in broiler chicken flocks in Canada, 2013-2015.

There is a paucity of data on the reason for and the quantity of antimicrobials used in broiler chickens in Canada. To address this, the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) implemented surveillance of antimicrobial use (AMU) and antimicrobial resistance (AMR) in broiler chicken flocks in 2013. Shortly after this (2014), the poultry industry banned the preventive use of ceftiofur in broiler chickens. The objectives of this analysis were to describe antimicrobial use (AMU) in Canadian broiler chickens between 2013 and 2015 (n = 378 flocks), compare these results to other animal species in Canada, to highlight the utility of farm surveillance data to evaluate the impact of a policy change, and to explore how different antimicrobial use metrics might affect data interpretation and communication. The surveillance data indicated that the poultry industry policy resulted in lower antimicrobial use and resistance, and they successfully captured information on when, where, why, and how much antimicrobials were being used. The majority of antimicrobials were administered via the feed (95%). The relative frequency of antimicrobial classes used in broiler chickens differed from those used in swine or in food animal production in general. Coccidiostats were the most frequently used antimicrobial classes (53% of total kg). Excluding coccidiostats, the top three most frequently used antimicrobial classes were bacitracin (53% of flocks), virginiamycin (25%) and avilamycin (21%), mainly used for the prevention of necrotic enteritis. Depending on the AMU metric utilized, the relative rankings of the top antimicrobials changed; hence the choice of the AMU metric is an important consideration for any AMU reporting. When using milligrams/Population Correction Unit (mg/PCU) the top three antimicrobial classes used were bacitracins (76 mg/PCU), trimethoprim-sulfonamides (24 mg/PCU), and penicillins (15 mg/PCU), whereas when using a number of Defined Daily Doses in animals using Canadian standards /1,000 chicken-days at risk (nDDDvetCA/1,000 CD) the ranking was bacitracins (223 nDDDvetCA/1,000 CD), streptogramins (118 nDDDvetCA/1,000 CD), and trimethoprim-sulfonamides (87 nDDDvetCA/1,000 CD). The median animal treatment days in feed for one cycle (ATD/cycle) during the three-year study were 34 ATD/cycle; this was equal to the mean age of the flocks at pre-harvest sampling day (days at risk), indicating that the studied flocks except those that were raised without antibiotics and organic, were fed with medicated rations throughout the observation period. Overall, more than half (59%) of antimicrobials used in broiler chickens were in classes not used in human medicine, such as ionophores and chemical coccidiostats aimed to prevent coccidiosis. Compared to grower-finisher pigs and in production animal species (national sales data), the mg/PCU of antimicrobials used in broiler chickens was relatively lower. The findings of this paper highlighted the importance of farm-level AMU surveillance in measuring the impact of interventions to reduce antimicrobials in poultry.

Estimated antimicrobial dispensing frequency and preferences for lactating cow therapy by Ontario dairy veterinarians.

In this cross-sectional study, data were collected from responses to a questionnaire on dispensing frequencies of antimicrobials used by dairy practitioners in Ontario in dairy cattle in 2001. Data were validated through clinical case scenarios. Respondents reported using antimicrobials across all categories of importance to human medicine (medically important, Categories I to III) with a diversity of treatment combinations and routes of administration. Respondents anticipated that a request for direct veterinary supervision by producers was dependent on case severity, highlighting the importance of on-farm diagnostic and treatment protocols. Knowledge of the antimicrobials used in lactating cow therapy, and their frequency and reasons for use, will provide baseline information and contribute to antimicrobial stewardship in this food-animal production sector.

Estimé de la fréquence de la distribution d'agents antimicrobiens et préférences pour le traitement des vaches laitières par les vétérinaires en Ontario. Cette étude en coupe transversale a été réalisée à partir de réponses recueillies d'un questionnaire qui ciblait les fréquences de dispense d'agents antimicrobiens utilisés chez les vaches laitières par les vétérinaires de la province d'Ontario en 2001. Ces données ont été validées avec l'aide de scénarios de cas cliniques. Les répondants ont indiqué l'utilisation d'antimicrobiens dans toutes les catégories qui sont jugées critiques en médecine humaine (dont les Catégories I à III) avec une diversité de combinaisons de traitements ainsi que de moyens d'administration. Les répondants ont anticipé que ce serait la sévérité d'un cas clinique qui déterminerait si le producteur devait faire une demande de supervision directe d'un vétérinaire sur la ferme. Ceci fait ressortir l'importance des protocoles de diagnostics et de traitements qui se feront dans chaque ferme. La connaissance des sortes d'agents antimicrobiens nécessaires, ainsi que la raison et la fréquence de leur utilisation en thérapie chez la vache laitière lactante, va fournir des renseignements de base et aussi contribuer à la gestion responsable d'agents antimicrobiens dans ce secteur de production animale.(Traduit par les auteurs).

Antimicrobial dispensing by Ontario dairy veterinarians.

This questionnaire-based cross-sectional study was designed to capture the demographics of dairy practitioners in Ontario and to describe aspects of antimicrobial dispensing on-farm and over-the-counter by these veterinarians. The information collected revealed that the prescription status of a drug and the level of veterinary-client-patient relationship were important elements of dispensing policies. Over-the-counter dispensing records were incomplete, while only a small proportion of on-farm dispensing records contained pertinent information and directions as required by the Veterinarians Act. While respondents recognized that antimicrobial use in dairy herds could lead to resistance in cattle, few indicated that this was a significant public health issue. Veterinarians can play a key role in antimicrobial stewardship, part of which is the provision of complete written dispensing instructions to producers for antimicrobial use in dairy cattle.

La distribution des agents antimicrobiens par les vétérinaires qui s'occupent des vaches laitières en Ontario. Cette étude en coupe transversale a été réalisée à partir de réponses recueillies d'un questionnaire qui ciblait les données démographiques des praticiens des fermes laitières de l'Ontario en plus de décrire les habitudes de dispense des doses d'agents antimicrobiens in situ par les vétérinaires ou en vente libre auprès des distributeurs. Cette information nous a permis de reconnaître que le statut de l'agent antimicrobien prescrit et le niveau de relation entre le vétérinaire-client-patient sont des éléments très importants de la politique de dispense. Les données concernant les agents antimicrobiens achetés sans prescription étaient incomplètes dans les points de vente et seulement une petite proportion des données internes à la ferme contenait les informations et les dosages tels que requis par la loi sur les vétérinaires. Les répondants reconnaissaient que l'utilisation des agents antimicrobiens chez les vaches laitières pouvait élever leur résistance à ceux-ci, mais peu d'entre eux mentionnaient que ceci engendrait une réelle inquiétude pour la santé publique. Les vétérinaires ont donc un rôle clé à jouer et ils devront être assidus en fournissant, par écrit, des instructions complètes sur les prescriptions d'agents antimicrobiens aux producteurs de vaches laitières.(Traduit par les auteurs).