Earlier quoted context omitted.
It's more about bacteria getting antibiotic resistence in animals and those get eventually passed to humans. Antibiotics are pretty much a non-renewable resource, the more they're used, the lesser their effectiveness. Using them on livestock, or even excessively on humans would leave humans with a dangerous lack of medical defence against harmful bacteria.
"It's more about bacteria getting antibiotic resistence in animals and those get eventually passed to humans." This can happen, but most of the bacteria found in animals are species-specific and don't get "passed" to us in the sense that you could "catch" flu or TB from another human. The real danger is "horizontal gene transfer" [1], where different kinds of bacteria exchange genes - including those for antibiotic r…
That effect might even have helped in conquering the Americas, because the conquerors where used to such diseases and the natives where not.