Antibiotic Use in Canadian Livestock

Antimicrobial resistance not limited to prescription overuse in humans

“Antimicrobial resistance continues to be a serious public health issue in Canada and internationally. Common and treatable infections may once again become deadly.”

These are the first words in the introduction of the Public Health Agency of Canada’s report Canadian Antimicrobial Resistance Surveillance System (CARSS) – Report 2016 published in September of this year.

Many Islanders have become aware of the grave warnings about antibiotics, more accurately called antimicrobials. These medicines are losing their effectiveness and there is a resurgence in drug-resistant infections. But most associate these concerns with the medical system (e.g. over-prescribing) and aren’t aware of how very closely this problem is tied to our food chain.

According to the report, Canada has approximately 19 times more livestock animals (i.e. used for food) than people. In 2014 over 80% of antimicrobials important to human medicine were distributed or sold for use in food-producing animals. These antimicrobials are used in animal production not just for treating disease, but also to prevent disease and improve feed efficiency/promote growth.

The report compared Canada to countries participating in the European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) network. Canada ranked 7th highest out of 27 countries for increasing levels of antimicrobial sales.

By comparison, the country with the lowest sales, Norway, bought 44 times less and Cyprus, the country with the highest sales, bought more than twice as much as Canada (figures adjusted by populations and weights).

Source: Canadian Antimicrobial Resistance Surveillance System (CARSS) - Report 2016

Source: Canadian Antimicrobial Resistance Surveillance System (CARSS) – Report 2016

 

The administration of antibiotics to food animals poses similar questions as it does with humans. Are the medicines being over-used? Are they being correctly administered? How often is a new, resistant strain developing within the animal being treated? Furthermore, there are concerns regarding how the waste of the animal is affected and how that might affect the environment if used for fertilizer.

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Source: Canadian Antimicrobial Resistance Surveillance System (CARSS) – Report 2016 Photo credit: Laura Weatherbie/Salty

In 2014, chicken and swine samples (on-farm, at slaughter, and at retail) positive for Salmonella spp. were 34% and 16% respectively.

As in E. coli, there was a drop in resistance to third generation cephalosporins in non-typhoidal Salmonella from chickens and chicken meat in 2014 compared to 2013.

For example, 22% of isolates from chickens sampled on-farm were resistant to third generation cephalosporins in 2013 but only 12% in 2014. By comparison, resistance to third generation cephalosporins in Salmonella from pigs was below 5% in 2014.

Antimicrobial use in feeds

Antimicrobial use in feeds

The report contains a few glimmers of progress. It says there is limited information on antimicrobial use in animals and some gaps in the surveillance of resistance in animals and the food chain, but new federal regulations expected in December 2016 should improve the scope of data from veterinary oversight of antimicrobial use.

In May 2014, the industry banned the preventive use of antibiotics used in human medicine (Category 1). Following this ban, the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) observed statistically significant decreases in resistant strains in cattle, swine, and chickens. The importance of this last piece of information should not be lost in the many facts within the report. Essentially, antibiotic resistant bacterial levels dropped when antibiotic use went down.

What does this imply for farming practices on PEI? What conclusions can be drawn from this data? What is our role as Canada’s Food Island?

Over the next few issues, Salty plans on digging deeper into PEI’s food chain to see what changes are being made, how this impacts local industries, and what individuals/groups on PEI are doing to address this issue. To be part of this discussion, please send your thoughts to info@saltyisland.com.

Source: Canadian Antimicrobial Resistance Surveillance System (CARSS) - Report 2016

Source: Canadian Antimicrobial Resistance Surveillance System (CARSS) – Report 2016