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Talk, tweet and shout about antibiotics for food animals

We've sat back long enough

Dr. Leigh Rosengren

We’ve sat back long enough

Sickness happens. When animals get sick they need treatment every bit as much as people. Retaining access to effective antibiotics for food animals is important for animal welfare and food safety because raising healthy animals means healthful, safe food.

This is an important message consumers need to hear from producers in the discussion on antibiotic resistance, says Dr. Leigh Rosengren, a veterinary epidemiologist who runs her own consulting firm from the family’s beef and grain farm near Midale, Sask.

“Antibiotic resistance is a threat to Canadians’ health. This isn’t a fear-mongering campaign made up by some marketing agency. It’s a true, honest and real threat,” she says. “It’s our responsibility as producers to explain what we do in Canada and on our ranches, particularly when consumers are afraid, occasionally misinformed and incredibly worried.”

Antibiotic resistance is about the ability of bacteria to resist a normally effective concentration of antibiotic.

Many antibiotics are produced in nature by fungi and bacteria. Ever since the beginning of time, bacteria have been evolving various defences that make them resistant to antibiotic substances as they compete for survival in their environments.

In this context, it’s easier to understand how antibiotic-resistant bacteria can turn up in animals that have never been treated with antibiotics and even in places where antibiotics have never been used to treat animals. It’s also why some antibiotics have never worked against some bacteria and never will. Sometimes bacteria have natural resistance to several antibiotics.

Though the use of antibiotic drugs in human and veterinary medicine isn’t the root cause of antibiotic resistance, it has been exacerbating the prevalence of antibiotic-resistant bacteria ever since penicillin from the Penicillium fungi became commercially available in the 1940s.

“So to be perfectly frank, we’ve all inherited a bit of a mess,” Rosengren says. Finger pointing by or at livestock producers isn’t going to solve this very complex issue that affects everyone and needs everyone on board working toward a common solution.

“Antibiotics are one of those common-good things; a societal resource, we all need to manage responsibly because when managed irresponsibly, the effect impacts us all,” she says. “Nobody understands stewardship of societal resources better than producers — the ethic of planning and managing a resource to leave it in a better state than those before us.”

Practice antibiotic stewardship daily, she urges, because all antibiotic use for people and animals will contribute to resistance. Antibiotics never kill 100 per cent of the target bacteria, nor the millions if not billions of other bacteria exposed to them during treatments. The survivors that have defences to the antibiotic go on to reproduce more of their kind. Some bacteria can collect and trade genes of resistance with other bacteria and pick them up from the environment via tiny plasmids that have nothing to do with their core genetics.

“I’m not saying don’t use antibiotics because sick animals need medicine, but before you pick up that bottle, think once, twice and three times whether the health benefit outweighs the burden on resistance,” she says. “Get your veterinarians involved because they have the training and resources to guide you down the road toward minimizing development of resistance in your herds.”

If resistance evolves, producers will need to move to more potent, more costly drugs and some of the most powerful antibiotics approved for use in cattle are also categorized by Health Canada as highly important and very important in human medicine.

If agriculture should lose access to the top antibiotics, due to resistance or regulation, there will be economic and animal welfare consequences because of increased sickness and death loss.

Antibiotic resistance is not the same as antibiotic residues and people need to know there are no antibiotics in Canadian meat, she stresses. Residues are chemicals that can easily be measured and that’s how withdrawal times are determined.

All veterinary drugs in Canada are licenced by Health Canada for specific species, uses and dosages with methods of administering them and withdrawal times stated on the labels. The Canadian Food Inspection Agency (CFIA) conducts routine testing at packing plants to make sure there are no antibiotic residues.

Shout back

Tweet the good news about what you do to raise healthy animals. She says it’s like night and day how vaccines and biosecurity have supplanted antibiotic use just in the past decade alone.

Let people know that beef producers have an antibiotic stewardship program as part of the Verified Beef Production program. It was introduced by the Canadian Cattlemen’s Association as Quality Starts Here in the early 2000s and after revisions to incorporate international HACCP standards and technical reviews by the CFIA, was rolled out with the new name in 2005-06. The producer manual, available to anyone online, includes standard operating procedures for animal health management, cattle shipping, medicated feed, pesticide control and training. The goal of the animal health management procedures is to minimize the risk of drug residues, antibiotic-resistant bacteria and broken needles in cattle.

Rosengren searched “antibiotics in meat” to find out what naysayers are shouting about and offered some facts of the matters to get out to consumers.

1. Agriculture uses 80 per cent of all antibiotics.

The organization that represents pharmaceutical companies in Canada does release some sales data, which show that most antibiotics used in animal agriculture are unrelated or unimportant in human medicine.

However, there isn’t a system in place to measure the distribution of pharmaceuticals or actual on-farm use by species in Canada or the U.S. She encourages producers to take every opportunity to participate in research on this topic because this is a weakness agriculture needs to address.

The 80 per cent figure started with a 2010 blog post by a U.S. researcher who simply subtracted U.S. pharmaceutical companies’ sales data on antibiotics for human use in the U.S. from that for use in food-producing animals in the U.S. Agricultural use did include ionophores, later said to account for one-third of the sales. The U.S. Food and Drug Administration issued a caution about the shortcomings of comparing the two figures this way.

2. Agriculture is simply using antibiotics to make animals grow faster.

In the early years, research sufficiently showed that adding small amounts of an oral antibiotic, such as tetracycline, to the ration improved both health and growth, so growth promotion was also approved as a label claim on some antibiotics approved for delivery through feed or water.

That’s about to become passé as pharmaceutical companies in Canada follow suit with their U.S. counterparts in voluntarily removing growth-promotion claims from therapeutic antibiotic labels.

Ultimately, the goal is to achieve labelling harmony with the U.S. so that the onus isn’t on Canadian veterinarians to decide on extra-label use, Rosengren explains. Label claims on some antibiotics approved in both countries are much broader in the U.S. than in Canada because Health Canada’s tight regulations make it burdensome for pharmaceutical companies to bring new products with wide label claims to Canada.

The products with the revised labels will still be available for therapeutic and preventative use. Consumers don’t understand the preventative approach because it’s not used in human medicine, she says. Beef production systems on the other hand are very predictable and often preventative use can be the most appropriate.

“If I have a pen of newly weaned calves and one starts to cough, I had better be proactive or I will have a pen of coughing calves. Is it humane to let them all get sick so I can prove they needed the drug when I predictably knew the whole pen would get sick and I delayed use of the small guns and now need to go in with the big guns?”

Removal of growth-promotion claims doesn’t apply to ionophores and other technologies that have gained favour over oral antibiotics for this purpose, those being hormonal ear implants and beta adrenergic agonists.

Ionophores are classified as a polyether antibiotic, not a therapeutic antibiotic. They have never been used in human medicine, therefore have no relevance in the resistance debate, Rosengren says. In ruminants, they improve feed efficiency in several ways, one of which is by reducing the methane-producing bacteria in the rumen that waste feed energy that would otherwise be available for growth.

3. Agriculture is creating superbugs that make us vulnerable to diseases we used to be able to cure.

Superbugs is a catchy word that refers to bacteria with resistance to more than one antibiotic.

The World Health Organization and Health Canada have stated that antimicrobial resistance in human medicine is primarily associated with the use of antimicrobials to treat human infections.

Antibiotics are one type of antimicrobial. They act specifically against bacteria, whereas antimicrobials include a broader range of substances, right down to common bleach and soap that kill bacteria, viruses, fungi or parasites.

One statistic that doesn’t get much publicity comes from the U.S. Centres of Disease Control (CDC). It estimates that 20 to 50 per cent of all antibiotics prescribed in U.S. acute-care hospitals are either unnecessary or inappropriate, stating that this misuse has contributed to the growing problem of antibiotic resistance. The CDC initiated an antibiotic awareness program in 2009 to promote improved use of antibiotics in hospitals and this year recommended that all acute-care hospitals implement antibiotic stewardship programs (ASPs).

Canadian hospitals are also taking this positive step. As of 2013, Accreditation Canada added ASP requirements to its program and Ontario has required ASPs for acute-care hospitals undergoing accreditation.

The Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) was set up to monitor trends in antimicrobial use and resistance to 15 antimicrobials in certain bacteria from human, animal (beef cattle, chicken, pigs) and their food products.

The latest results online (2011) show generic E. coli from retail ground beef as having negligible resistance to the highly important antibiotics and low resistance to the older drugs of lesser importance in human medicine. The levels of resistance to some antibiotics rise and fall through the years and in some cases were lower in 2011 than in 2003. This closely mirrored the pattern of resistance in abattoir samples taken from the beginning of the large intestine.

Rosengren summarizes a 2013 CDC report on antimicrobial resistance and threats that lists 18 bacteria for which antibiotic resistance is considered to be urgent, serious or of concern. None of them have anything to do with agriculture. Only three of the serious threats relate to agriculture through foodborne exposure, and none of the threats of concern relate to agriculture.

“Yes, it can be very serious if someone gets resistant bacteria from meat, but the probability of that happening in Canada is infinitely small because we have incredibly good programs in slaughter plants, good kitchens and we know how to handle and cook meat,” Rosengren says. Remember, foodborne bacteria are not resistant to heat. Proper cooking destroys them.

People need to understand, too, that concern is not the same as risk, she says. It’s a long journey from farm to fork and then a resistant bacteria would have to actually cause illness and be resistant to the drug of choice for treatment.

In the U.S., a risk assessment followed the chain from farm to fork and estimated that the human health impact from flouroquinolone use in dairy cattle was one case in 13 years for campylobacter and one case in 293 years for salmonella.

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