April 7, 2013 • 1 min
Farmers in many countries utilize antibiotics in two key ways: at full strength to treat animals that are sick and in low doses to fatten meat-producing livestock or to prevent veterinary illnesses. Although even the proper use of antibiotics can inadvertently lead to the spread of drug resistant bacteria, the habit of using a low dose is a formula for disaster: the treatment provides just enough antibiotic to kill some but not all bacteria. The germs that survive are typically those that happen to bear genetic mutations for resisting the antibiotic. They then reproduce and exchange genes with other microbial resisters. As bacteria are found literally everywhere, resistant strains produced in animals eventually find their way into people as well. You could not design a better system for guaranteeing the spread of antibiotic resistance. To cease the spread, Denmark enforced tighter rules on the use of antibiotics in the raising of poultry and other farm animals. The lesson is that improving animal husbandry – making sure that pens, stalls and cages are properly cleaned and giving animals more room or time to mature – offsets the initial negative impact of limiting antibiotic use.