Andrea Turner

Antimicrobial use in food-producing animals: a rapid evidence assessment of stakeholder practices and beliefs

Food-producing animals throughout the world are likely to be exposed to antimicrobial (AM) treatment. The crossover in AM use between human and veterinary medicine raises concerns that antimicrobial resistance (AMR) may spread from food-producing animals to humans, driving the need for further understanding of how AMs are used in livestock practice as well as stakeholder beliefs relating to their use. A rapid evidence assessment (REA) was used to collate research on AM use published in peer-reviewed journals between 2000 and 2016. Forty-eight papers were identified and reviewed. The summary of findings highlights a number of issues regarding current knowledge of the use of AMs in food-producing animals and explores the attitudes of interested parties regarding the reduction of AM use in livestock. Variation between and within countries, production types and individual farms demonstrates the complexity of the challenge involved in monitoring and regulating AM use in animal agriculture. Many factors that could influence the prevalence of AMR in livestock are of concern across all sections of the livestock industry. This REA highlights the potential role of farmers and veterinarians and of other advisors, public pressure and legislation to influence change in the use of AMs in livestock.

Ceasing the use of the highest priority critically important antimicrobials does not adversely affect production, health or welfare parameters in dairy cows

Due to scientific, public and political concern regarding antimicrobial resistance (AMR), several EU countries have already taken steps to reduce antimicrobial (AM) usage in production animal medicine, particularly that of the highest priority critically important AMs (HP-CIAs). While veterinarians are aware of issues surrounding AMR, potential barriers to change such as concerns of reduced animal health, welfare or production may inhibit progress towards more responsible AM prescribing. Farmers from seven dairy farms in South West England engaged in changing AM use through an active process of education and herd health planning meetings. Prescribing data were collected from veterinary sales records; production and health data were accessed via milk recording and farm-recorded data. This study demonstrates that cattle health and welfare—as measured by production parameters, fertility, udder health and mobility data and culling rates—can be maintained and even improved alongside a complete cessation in the use of HP-CIAs as well as an overall reduction of AM use on dairy farms. This study also identified a need to consider different metrics when analysing AM use data, including dose-based metrics as well as those of total quantities to allow better representation of the direction and magnitude of changes in AM use.

Embolic pneumonia in adult dairy cattle associated with udder cleft dermatitis

WE wish to report a number of cases of pneumonia in adult dairy cows that were associated with embolic spread from abscessation cranial to the udder, in turn preceded by udder cleft dermatitis (UCD) – also known as udder intertrigo and ulcerative mammary dermatitis. UCD is a moist dermatitis mostly seen between the anterior of the udder and the abdomen, but also between the front quarters (Bouma and others 2016). It can present with a pungent odour, take many weeks to resolve and is more common in older cows (Warnick and others 2002). High-yielding cows which have calved at least three times are more likely to develop UCD (Waller and others 2014), and cows with a deep udder and a small angle between the udder and abdominal wall are more likely to be affected (Olde Riekerink and others 2014). It has been proposed that the treponemes associated with digital dermatitis (DD) are also involved in the pathogenesis of UCD. However, the aetiology of UCD is likely to be more polymicrobial than DD (Evans and others 2010) and the exact cause of this condition has not been determined. Embolic pneumonia results from haematogenous spread from an infected focus elsewhere in the body, with the most common source …

Evaluation of metrics for benchmarking antimicrobial use in the UK dairy industry

The issue of antimicrobial resistance is of global concern across human and animal health. In 2016, the UK government committed to new targets for reducing antimicrobial use (AMU) in livestock. Although a number of metrics for quantifying AMU are defined in the literature, all give slightly different interpretations. This paper evaluates a selection of metrics for AMU in the dairy industry: total mg, total mg/kg, daily dose and daily course metrics. Although the focus is on their application to the dairy industry, the metrics and issues discussed are relevant across livestock sectors. In order to be used widely, a metric should be understandable and relevant to the veterinarians and farmers who are prescribing and using antimicrobials. This means that clear methods, assumptions (and possible biases), standardised values and exceptions should be published for all metrics. Particularly relevant are assumptions around the number and weight of cattle at risk of treatment and definitions of dose rates and course lengths; incorrect assumptions can mean metrics over-represent or under-represent AMU. The authors recommend that the UK dairy industry work towards the UK-specific metrics using the UK-specific medicine dose and course regimens as well as cattle weights in order to monitor trends nationally.

Two cases of embolic pneumonia associated with udder cleft dermatitis in dairy cattle from the same farm

Two Holstein cows from the same farm were presented within eight months of each other with malaise, milk drop and dyspnoea. Both cows had active or historic udder cleft dermatitis (UCD) lesions. Clinical examination and diagnostic tests led to an initial diagnosis of chronic suppurative pneumonia in both cows. The cases were poorly responsive to antibiotic treatment and died or were euthanased, 18 and 16 days respectively, after presentation. Postmortem examination of each case resulted in the diagnosis of embolic pneumonia associated with UCD. In both cases, UCD lesions, which were considered insignificant by the farmer and the veterinarian, are thought to have been the initiating source of infection. It is important that both farmers and vets are made aware of the possible severe consequences of udder cleft lesions and that early detection strategies for UCD and udder cleft lesions are adopted and implemented on-farm.

Evaluation of Metrics for Benchmarking Antimicrobial Use in the United Kingdom Dairy Industry

The issue of antimicrobial resistance is of global concern across human and animal health. In 2016 the UK government committed to new targets for reducing antimicrobial use (AMU) in livestock. However, though a number of metrics for quantifying AMU are defined in the literature, all give slightly different interpretations. This paper reviews a selection of metrics for AMU in the dairy industry: total mg, total mg/kg, daily dose and daily course metrics. Although the focus is on their application to the dairy industry, the metrics and issues discussed are relevant across livestock sectors. In order to be used widely, a metric should be understandable and relevant to the veterinarians and farmers who are prescribing and using antimicrobials. This means that clear methods, assumptions (and possible biases), standardised values and exceptions should be published for all metrics. Particularly relevant are assumptions around the number and weight of cattle at risk of treatment and definitions of dose rates and course lengths; incorrect assumptions can mean metrics over- or under-represent AMU. The authors recommend that the UK dairy industry work towards UK-specific metrics using UK-specific medicine dose and course regimens as well as cattle weights in order to monitor trends nationally.

Does inclusion of glutamine in oral rehydration solutions improve recovery from mild to moderate diarrhoea in preweaned calves

Critically Appraised Topics (CATs) are a standardised, succinct summary of research evidence organised around a clinical question, and a form of evidence synthesis used in the practice of evidence-based medicine (EBM) and evidence-based veterinary medicine (EBVM). Access to CATs enables clinicians to incorporate evidence from the scientific literature into clinical practice and they have been used to teach EBVM at the University of Bristols School of Veterinary Sciences since 2011. Veterinary Record is including CATs from Bristol university in its Clinical Decision Making section. The first of these, along with an explanation of how they can be used, was published in VR, January 30, 2016, vol 178, pp 118-119.