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Food Animal Matters
June 20, 2025
The publication of this column marks the end of the second year since the publishers of The Canadian Veterinary Journal graciously allowed me to coordinate a column that addressed issues uniquely or predominantly affecting veterinarians in food animal practice. I have tried to give willing food animal veterinarians an opportunity to present information about their professional lives. I am deeply appreciative of all those food animal veterinarians who shared their practice experiences through Food Animal Matters, thank you. This column addresses a topic that impacts food animal veterinarians to a much greater extent than veterinarians in almost all other forms of practice, although veterinarians in educational settings should also be attentive since their actions may very well be seen as those of a role model by their students.
Food Animal Veterinarians And Antimicrobial Use In Food Animal Production. Part 1
These are 2 issues that many food animal veterinarians find uncomfortable discussing. They often feel caught in the crosshairs whenever someone brings these issues up. Many feel stuck in the middle trying to figure out how to satisfy all the players in these discussions yet still provide good professional advice to their clients. Even though these topics might make many food animal veterinarians uncomfortable, antimicrobial resistance (AMR) and antimicrobial use (AMU) are 2 issues of increasing social concern, so they are not likely to go away anytime soon.
In September, 2024, the United Nations General Assembly (UNGA), representing global consensus, approved a political declaration related to AMR. The political declaration began by stating that “…..antimicrobial resistance is one of the most urgent global health threats and development challenges and demands immediate action to safeguard our ability to treat human, animal, and plant diseases, as well as to enhance food safety, food security and nutrition, foster economic development, equity and a healthy environment….” The 15-page declaration document went on to outline a series of commitments in several subject areas including human medicine but also agriculture and animal health; environment; and surveillance and monitoring (1).
In 2023, the Public Health Agency of Canada (PHAC) had published and committed to the Pan-Canadian Action Plan on Antimicrobial Resistance (2). The Action Plan assumes a One Health approach stating that “Antimicrobials … help protect animal health and welfare, and play a critical role in Canada’s agriculture and food production systems. Increasing AMR can impact the health of food-animals and lead to reduced productivity and food safety concerns. An effective response to AMR requires joint One Health action across sectors and jurisdictions, both in Canada and globally.”
The action plan calls for commitments by federal, provincial, and territorial governments “…on AMR over the next 5 y (2023 to 2027). Ten priority actions will guide Canada’s multi-sectoral and multi-jurisdictional efforts across 5 pillars: research and innovation; surveillance; stewardship; infection prevention and control (IPC); and leadership.”
The PHAC had already been active on AMR/AMU prior to 2023. Beginning in 2002, the PHAC had been monitoring AMR through the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) (3). The PHAC describes CIPARS activities as collecting, analyzing, and communicating trends in antimicrobial use and in antimicrobial resistance amongst select bacteria collected from humans, animals, and retail meat samples. The CIPARS also collects data on the sales of antimicrobial for use in humans, animals, and plants/crops. The CIPARS also collects data on AMU on sentinel farms using various methods and through Fisheries and Oceans Canada, they report on AMU in all aquaculture operations.
The PHAC data show that a large majority of antimicrobials sold in Canada are intended for use in food-producing animals and horses. More detailed antimicrobial sales data are collected in one of the CIPARS components called Veterinary Antimicrobial Sales Reporting (VASR) (4). The data collected in VASR are a collaborative effort between PHAC and Health Canada’s Veterinary Drugs Directorate. The VASR started collecting sales data shortly after Canadian regulations were implemented that required all antimicrobial sales to be accompanied by prescriptions and therefore be under the control of veterinarians. Prior to that change, some antimicrobials could be sold over the counter (referred to as OTC).
Commodity-specific sales data are summarized and have been published annually since 2019 (for 2018 sales). Sales data are also reported according to the classification of each antimicrobial’s importance to human health. Health Canada recognizes 3 categories of medically important antimicrobials:
- Category 1 — antimicrobials of very high importance in human medicine;
- Category 2 — antimicrobials of high importance to humans; and
- Category 3 — antimicrobials of medium importance (5).
There is also a 4th category for antimicrobials of low importance. Summaries of these sales data are accessible to the public (6).
Tracking or measuring AMU is a critical requirement for changing patterns of AMU. Unfortunately, there is no international agreement on a standard method to measure AMU. Even so, it is important to track it no matter if the measurement tools are themselves imperfect. The CIPARS-VASR reports on total kilograms of antibacterials sold. This is a very difficult measure to interpret because dosage rates differ so much between different antimicrobials. The CIPARS-VASR also reports sales using 3 other methods that each adjust the amounts sold to consider population size and the weight of the animals in the commodity. Since there are clear differences in the medical importance of individual antimicrobials, VASR also reports sales volume according to the importance of the antimicrobials in human medicine as designated by Health Canada.
Trends observed in the CIPARS-VASR data have been that total antimicrobial sales have decreased since 2018, although there are year-to-year variations in total sales, in sales by animal production type, and in sales by region of Canada. The 2023 data showed that most antimicrobials sales for use in production animals were delivered in feed or in water (,90%) with only a small percentage delivered by methods commonly used when treating individual animals. Although there are opportunities to influence total sales by targeting the treatment of individual animals, there are likely more opportunities by examining the use of antimicrobials delivered in feed and water.
As important as it may be to reduce overall usage, it is likely equally important to consider how antimicrobials designated as important in human medicine are used in veterinary medicine. This is also an area in which changes to patterns of antimicrobial treatments of individual animal treatments, as opposed to treatment of groups, could impact total AMU. The VASR data show that sales of antimicrobials in Categories 2 and 3 declined between 2018 and 2023. Sales of Category 1 antimicrobials increased over that time.
It is important to note that in October 2023, the Auditor General of Canada released a report on the Canadian government’s responses on antimicrobial resistance. The report addresses human and veterinary use. In the summary of that report, the Auditor General pointed out, what are considered to be gaps in the Pan-Canadian Action Plan on Antimicrobial Resistance including a lack of “concrete deliverables, timelines, and details about who is accountable for each action” (7). Even so, the top recommendation in the report was that all parties should work together to assure the implementation of the Action Plan.
Also amongst the top recommendations was a call for Health Canada to finalize its review of veterinary antimicrobials that have unspecified or prolonged durations of use and to prioritize changes to the labels of those antimicrobials according to their importance in human medicine and by how often they are sold for veterinary use. This recommendation is obviously targeted at antimicrobials prescribed by veterinarians for delivery in feed and water.
The Auditor General’s report also brought up a serious issue that affects both human and veterinary medicine in Canada. That issue is access to antimicrobial drugs. In veterinary medicine, it is often difficult to access suitable formats of antimicrobial drugs in Category 2 and Category 3. In some clinical situations, the only available therapeutic option is an antimicrobial in Category 1. Even if veterinarians wanted to avoid treating with a Category 1 antimicrobial, they might have no other options. This certainly limits how much veterinary practitioners can alter their patterns of AMU.
In the next 2 columns, 3 veterinarians will describe initiatives to change patterns of AMU in poultry and livestock. In this month’s column, Dr. Bill Cox, a veterinarian with a long professional career in the poultry industry, relates how the industry succeeded in completely eliminating the use in poultry production of all antimicrobials categorized as Category 1 and Category 2 for disease prevention.
In the next column, 2 veterinarians from Quebec will describe the impact of regulations on AMU in their province that set conditions on the use of Category 1 antimicrobials. Sufficient time has passed since the introduction of those new regulations that it is possible to evaluate the impact of the change on veterinarians in their day-to-day practice activities and on farmers.
Impact Of Category 1 Antimicrobial Regulations For Poultry Veterinarians
Bill Cox, DVM
In its earliest days, poultry farming was underserved by the veterinary profession. Farmers were often left to rely on over-the-counter medications for disease control. Over time, as antimicrobial resistance became a global concern, poultry farming emerged as a perceived contributor to the problem, despite very low dose-per-animal use, particularly for Category 1 antimicrobials.
With mounting evidence of antibiotic resistance, including among poultry pathogens, the industry adopted a more critical stance on antimicrobial use. Regulatory changes followed. In 2017, mandated by Health Canada, all antimicrobials in Categories 1, 2, and 3 became prescription-only for veterinary use in Canada. Importantly, antimicrobials classified as Category 1 — reserved for critical human health needs — had not been approved for use in poultry for over a decade. They were already restricted to prescription-only, off-label use.
Proactively, the poultry sector took decisive action before the regulatory mandates. In 2014, organizations such as Chicken Farmers of Canada and Turkey Farmers of Canada voluntarily banned the use of Category 1 antimicrobials for preventive purposes in chickens and turkeys. This decision notably removed ceftiofur, a Category 1 antimicrobial, from hatchery practices like in ovo or dayof- hatch injections aimed at preventing early chick mortality. By 2018, the industry extended this voluntary ban to Category 2 antimicrobials for preventive use.
Despite these shifts, the impact on veterinary practice has been limited. Antimicrobial sales to poultry producers represent only a small fraction of total veterinary clinic income. Moreover, the core ability of poultry veterinarians to provide effective treatment has not been significantly disrupted. Prescription-only access ensures veterinarians retain the necessary tools to treat poultry diseases responsibly.
The removal of certain antimicrobials for disease prevention has been more keenly felt by producers. The specter of preventable disease, both clinical and subclinical — most notably necrotic enteritis caused by Clostridium perfringens — has become a serious concern. However, this challenge has also spurred positive change. Veterinarians and producers alike have adopted a more judicious approach to antimicrobial use, emphasizing improved management practices and preventative tools over reliance on pharmaceuticals.
Although regulatory changes have led to progress in responsible antimicrobial stewardship, one critical challenge remains: the lack of access to new antibiotics of little importance to human medicine and viable alternatives to antibiotics. Veterinarians are increasingly limited by a regulatory environment that lags in approving new tools available elsewhere in the world. A streamlined, modernized regulatory approach to identify and approving of novel solutions — be they antimicrobial, probiotics, or other innovations — is urgently needed.
The removal of Category 1 antimicrobials for preventative use marks a significant milestone in the poultry industry’s commitment to combating antimicrobial resistance. Although the impact on veterinary practice has been minimal, producers face ongoing challenges. Moving forward, sustainable success will depend on fostering innovation and ensuring access to effective, approved antimicrobials and alternatives to help maintain health.