Parecido com o problema nos humanos:
http://www.pig-world.co.uk/news/animal-health/farm-antibiotics-investors-are-right-to-be-worried.html
"The need to tackle human prescribing is still widely considered to be the highest priority in the drive to safeguard our antibiotics, but global attention is increasingly turning to the overuse of antibiotics in farming.
The discovery in late 2015 of the mcr-1 gene, which confers resistance to the “last-resort” antibiotic colistin, catapulted veterinary antibiotic use into the headlines worldwide. First found in China, the gene was subsequently discovered in at least 19 countries worldwide.
These findings, strongly linked to farm use of colistin, triggered widespread concern. Subsequently, 50 medics and scientists across Europe and the US called on MEPs to support a ban on routine preventative mass-medication of groups of healthy animals."
