Antibiotics and resistance

Antibiotics are a type of antimicrobial medication used to fight bacterial infections in people and animals.

Antibiotic resistance occurs when the bacteria change and develop the ability to survive exposure to the antibiotics used to treat them. As a result, the medication is no longer effective in killing or slowing the growth of a specific disease-causing organism. It’s an important issue worldwide, because it makes it harder to fight human and animal infections caused by these resistant bacteria.

Antimicrobial resistance is a natural phenomenon which can be made worse by environmental contamination, misusing antibacterial cleaning products, and using antibiotics in human or animal medicine too much or incorrectly.

Health Canada has established four categories of antimicrobials based on how they are used in human medicine, ranging from Category I (“very high importance”) to Category IV (“low importance”). The Canadian government tightened the rules on antimicrobial use in farm animals in 2018. For example, farmers now need a veterinary prescription to buy any Category I, II, and III products, and using any of these products to promote growth has been banned. Advances in animal housing, nutrition, and biosecurity practices mean that fewer antibiotics are used today than in past decades.

The bottom line on antibiotics

Antibiotics are a valuable tool for treating sick people and animals, so it is important that everyone uses them responsibly. Resistance is a complex topic, and critically important research into resistance is happening around the world in both human and animal medicine.

What about drug residues?

Drug residues are traces of medication left over in meat, milk, or eggs, after an animal has been treated with a medication. Every animal health product (e.g. antimicrobials, vaccines, supplements) has what is called a “withdrawal period”—a specific amount of time a farmer must wait before sending a treated animal or its products to market. This ensures that food is safe and free of residues. As an added layer of security, processing plants also test for drug residues to ensure food safety.