“In the intervening years, the scientific evidence of the risks to human health from the widespread use of antibiotics in livestock has grown, and there is no evidence the F.D.A. has changed its position that such uses are not shown to be safe,” Judge Katz wrote in his order.
Eighty percent of antibiotics bought in the United States are used in animals, not humans. Meanwhile, outbreaks of illnesses from antibiotic-resistant bacteria have grown in number and severity, killing thousands.
Environmental and health groups petitioned the F.D.A. in 1999 and 2005 to restart the process to ban the drugs for promoting animal growth. The Natural Resources Defense Council, the Center for Science in the Public Interest, the Food Animal Concerns Trust, Public Citizen and the Union of Concerned Scientists filed suit against the F.D.A.
On Thursday, Judge Katz ruled that these groups had won their case without need for a trial.
Judge Katz ordered the F.D.A. to alert drug manufacturers that it intended to prohibit the use of penicillin and tetracycline to promote growth in animals.
Factory-farm industry groups are unconcerned, easily side-stepping the ruling. They don't use antibiotics for growth, but as a prophylactic against disease. The ruling does not specifically prevent this.