What’s happening with antibiotic stewardship and where do farmers fit in?

Changes are afoot when it comes to the use of antibiotics in livestock production. Growing concern over antimicrobial resistance is behind a new federal framework released last fall, and everyone in the industry has a role to play to ensure farmers will still have access to needed medication.

That’s according to Dr. Dave Léger, of the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) with the Public Health Agency of Canada. CIPARS is a group of veterinary epidemiologists based in Guelph, Saskatoon and St. Hyacinthe that provides surveillance of antimicrobial use and antimicrobial resistance across all major livestock commodities in Canada.

Dr. Dave Léger

When speaking at the 2016 Healthy Calf Conference, Léger cautioned that antimicrobial resistance (AMR) mitigation is not about residue avoidance, but rather a biological hazard that can continue beyond a residue withdrawal period.

“You can still spawn resistance even if you use a product on label and follow withdrawal times,” he explained. “It’s more complex than residues and requires a multi-prong approach.”

In human medicine, antibiotics are grouped in categories of importance with one being the most important. Category two and three medications are commonly used, whereas category one antimicrobials are considered a “last-resort-use” that doctors only fall back on when drugs in lower categories have not been effective a treating an illness.

The Veterinary Drug Directorate, which governs veterinary medicines, refers to the top three category antibiotics as medically important antimicrobials, whereas category four products are of low importance and have no counterpart in human medicine.

“The system is already working as we see higher category drugs being used mostly in humans and vets using lower category drugs more actively,” he stated, referring to antimicrobial use data.

Resistance is relatively modest when looking at beef abattoir and retail samples, he said, with tetracycline typically seen in almost every commodity as a prevalent resistance pattern.

CIPARS conducts core surveillance in swine, broiler poultry and beef, with periodic surveys in other commodities like veal and turkey.

A year ago, the federal government released a new framework for antimicrobial resistance mitigation which is based on three pillars: surveillance (monitoring), stewardship (prevention and control) and innovation (new methods and tools).

In order to preserve use of antimicrobials and their efficacy, it’s critical that government work with animal agriculture sector partners to encourage the use of antimicrobial alternatives and the adoption of new practices that will reduce the use of these products, Léger said, as well as strengthening understanding of when it is appropriate to use antimicrobials in both human and livestock medicine.

Globally, an estimated 70 to 80 per cent of all antimicrobials are used in food-producing animals, and although Health Canada is responsible for authorizing the sale of veterinary drugs, their use falls under provincial authority. This means a multi-jurisdictional approach is needed to address the problem, Léger said.

The Veterinary Drug Directorate currently has five AMR initiatives underway, some of which are new regulatory proposals and others that are simply an expansion of existing regulations:

  • Increased oversight on own-use importation, with no importation of medically important antimicrobials (MIA)s allowed for use in food-producing animals.
  • Oversight of importation and quality of active pharma ingredients by applying the human medicine framework to veterinary drugs.
  • Reporting of annual volumes veterinary antimicrobial sales. This data is currently only voluntarily collected through the Canadian Animal Health Coalition.
  • Easier access for veterinarians and farmers to alternative health products that can help maintain animal health and welfare.
  • Removal of growth promoting claims on labels. This means moving all over the counter drugs to a prescription drug list that would require prescriptions for all antimicrobials.

“There are regulations in each province that need to be changed and updated,” Léger said. “The timelines are not carved in stone but we are looking at a 2018-19 rollout for much of this.”

The five Rs of antimicrobial stewardship can go a long way to reduce resistance and preserve the efficacy of these medications:

  • Responsibility: “As end users, we have to look ahead and do a risk-benefit analysis to determine what the potential impacts of resistance are that could have an animal or public health outcome,” Léger said.
  • Reduction: “This means reducing or rationalizing our use by decreasing the percentage of medicated rations, the duration of exposure, and introducing management and husbandry changes,” Léger explained.
  • Refining: “We want to be refining our protocols and practices on an ongoing basis for the right drug at the right time and the right dose for the right duration,” Léger stated.
  • Replacement: “We need to look for some non-antimicrobial alternatives,” Léger said.
  • Reviewing: “Regular and continuous improvement is important,” he added.