Thirteen senators from both sides of the political aisle in a letter asked US Food and Drug Administration Commissioner Margaret Hamburg to collect more data on antibiotics used in food animal production.
As the Food & Drug Administration has noted before, the agency does not have detailed data about veterinary drug usage. Antibiotics sales are reported to FDA, but the agency does not collect any data on which species are treated and what percentage of the drugs are used for disease prevention, growth promotion or therapeutic treatment.
Without this data, it is nearly impossible to accurately track whether the industry is reducing its usage of medically important antibiotics - which scientists and public health advocates have long argued would help combat antibiotic resistance.
"This is of great concern to us, and we urge the agency to design a system with relevant agencies and stakeholders for gathering and analyzing necessary information to assess the effectiveness of the new policies," read the letter.
"Should you find any critical gaps in your statutory authority, we would welcome the opportunity to work with you to provide additional authorities and resources," the senators wrote.
They commended FDA for asking drug companies to revise their antibiotic labels to eliminate "growth promotion" uses and for increasing veterinary oversight over the use of antibiotics in livestock. But they also expressed concern about the "considerable ambiguity" regarding the agency's policies.
The guidance documents consider the use of antibiotics for "disease prevention" as a judicious use of the drugs.
"If broadly defined, 'disease prevention' could allow the continued use of antibiotics in ways not consistent with FDA's vision for 'judicious use,'" continued the letter.
"This could include inappropriate and ineffective practices that merrily mask underlying production problems such as poor hygiene or animal overcrowding."