Abstract
Background: There are currently several voluntary guidelines and recommendations that aim to
promote the responsible use of antimicrobials (AMU) and to reduce misuse of these medicines in both
food-producing animals and companion animals. They have been developed by a number of
organisations and implemented in several European countries with the aim of reducing the impact of
AMU on antimicrobial resistance (AMR). However, the extent of implementation of these guidelines
and their effectiveness in changing behaviours associated with AMU are unknown in most cases. This
review assesses the extent of implementation of guidelines, and the impact of these on levels and
patterns of AMU in food-producing animals and companion animals in order to inform the
development and implementation of better voluntary approaches for reducing AMU in the animal
health sector.
Methods: Databases including Science Direct and MEDLINE were searched for studies assessing the
extent of implementation and impact of guidelines on levels and patterns of AMU in food-producing
animals and companion animals. Additional searches using reference tracking, snowballing and grey
literature were also performed. Quality of evidence and risk of bias assessment were conducted. A
narrative synthesis approach was followed to assess and present the evidence gathered across eligible
studies.
Results: A total of 784 studies were screened. Fourteen studies were deemed eligible for inclusion.
All, apart from three, were conducted in Europe. Several voluntary guidelines on prudent AMU were
referred to in these studies, mostly developed by international or regional bodies. There is limited
evidence on the extent of implementation and the effectiveness of these guidelines in food-producing
animals and companion animals. In food-producing animals, the quality of studies was deemed low as
most were cross-sectional and based on convenience sampling. There were differences in uptake of
prudent AMU guidelines including use of antimicrobial susceptibility testing (ASTs) and critically
important antimicrobials (CIAs) among countries. Voluntary initiatives from levy bodies supporting
farmers involving reduction and ban of use of CIAs (e.g. third generation cephalosporins), combined
with changes in animal husbandry and farming practices, and improvement of vaccination strategies
were deemed amongst the most effective in the swine (UK and Denmark) and poultry (UK) sectors,
and to a lesser extent in the dairy cattle production sector (Denmark). There may be lessons to be
learnt from these countries for more effective AMU reduction strategies. Nevertheless, there are still
scarce data on the potential impact of voluntary interventions on animal health and welfare, and
productivity. One of the few countries to have assessed the impact of the promotion of prudent use
campaigns, on animal health and welfare, and productivity was Denmark which has recently reported
that their impact waslow in the short term according to surveillance data, though further assessments
are required to assess impact in the long-term. There was even less evidence available for companion
animals, and the quality of studies was lower; as consequence, these studies were not deemed
suitable for the assessment of impact of prudent use recommendations and guidelines.
Conclusions: Prudent use guidelines are available in most European countries, at different levels:
international (Europe-wide); national (countrywide or for members of associations); and local (e.g. at
hospital level). In some countries like the UK, the livestock and poultry industries have taken the
initiative to reduce the use of AMs by adopting national and international recommendations for the
reduction of use the use of critically important antimicrobials. However, there is currently limited
quantitative evidence of the impact of the recommendations voluntary interventions in AMU in both
food-producing and companion animals, and, particularly, their impact on animal health and welfare,
and productivity. This is due to the lack of systematic assessment of surveillance data and of
longitudinal studies to investigate the effectiveness of guidelines in changing antibiotic use in animal
populations the promotion of prudent AMU. Targeted adoption of prudent use practices by farmers
and veterinarians were reported to be an effective approach to reduce AMU, including CIAs in poultry,
swine and dairy cattle.