The world’s largest animal drugs company has been accused of double standards and of fuelling the development of superbugs by selling antibiotics to farmers in India for purposes now banned in Europe and America.

Zoetis, a former subsidiary of the drugs giant Pfizer, is supplying farmers in India with antibiotics to help them artificially fatten up livestock including chickens.

The World Health Organization (WHO) has called for the practice to be banned worldwide because it increases the prevalence of resistant bacteria that can infect humans and cause deadly and untreatable infections.

The American company stopped advertising antibiotics as growth promoters to American farmers nearly two years ago. Zoetis publicly supported new laws in the US banning this abuse of antibiotics as part of its “continued commitment to antibiotic stewardship”. However, Zoetis is continuing to sell antibiotics directly to Indian farmers with claims on the company’s Indian website that it will make animals grow bigger and faster.

This is not currently against Indian law although the Indian government has called for it to end and the second biggest state, Maharastra banned the indiscriminate use of antibiotics in agriculture after a Hindu/Bureau story earlier this year.

Dr Abdul Ghafur, a professor in infectious diseases who brought together medical societies and the Indian government in 2012 to create a plan to tackle antibiotic resistance, known as the Chennai Declaration, said Zoetis is using “double standards”.

“If an American company follows one policy in America, they should follow the same policy in India,” he said.

Dr Thomas Van Boeckel, a researcher at the Swiss Federal Institute of Technology (ETH Zurich) who has mapped antibiotic use in agriculture, said: “It is blatantly clear that Zoetis is using a double standard in the way it is willing to expose consumers in India to higher levels of risk than in the United States.” Zoetis says it complies with the law in each location where it operates.