Higher number not necessarily due
to more cases, spokesman says
By MATEUSZ PERKOWSKI
Federal regulators sent significantly more warning letters last year to farmers about illegal drug residues in livestock than during the previous year.
The U.S. Food and Drug Administration issued 77 warning letters over illegal drug residues to livestock producers in 2012, up from 42 the prior year.
Such letters urge companies to voluntarily correct alleged violations, but the agency can take further enforcement action if they fail to comply with food safety laws.
Inspectors from the USDA test meat and notify the FDA if drug residues exceed levels that are considered safe, said Bill Flynn, deputy director of science policy at the FDA's Center for Veterinary Medicine.
The number of warning letters sent to livestock producers is "resource-driven," so the increase in 2012 doesn't necessarily mean that illegal drug residues are growing more common, he said.
The FDA can't investigate every violation, so it puts more resources into cases that are considered most concerning based on drug toxicity, the residue level and whether the farm had previous violations, Flynn said.
While the number of violations within the industry overall is low, most are related to dairy cows that have been culled for slaughter, he said.
Culled dairy cows are more likely to have been sick before slaughter, which often means the farmers has unsuccessfully tried to treat them with medications, Flynn said.
"These animals are being removed from their herd for a reason," he said.
Violations occur when farmers use higher doses than allowed or don't follow the mandatory withdrawal times for the drug before the animal is sent to slaughter, Flynn said.
Farmers can also lose track of which animals have been medicated, he said. "A common thread we find with these violations is there's insufficiency in record-keeping and animal ID procedures."
In some cases, problems can occur when too much volume of medicine is applied at one site on the animal, said Troy Downing, dairy extension specialist at Oregon State University.
This can slow down the metabolic breakdown of the substance compared to administering the drug at multiple sites, he said. Label information usually prevents farmers from making such mistakes.
It also helps to review protocols with veterinarians to avoid applying wrong doses or an inappropriate drug, Downing said. "It's a costly and ineffective way to use products."
The FDA's primary concern is minimizing potential toxicity to humans from the drug, Flynn said. The hazard depends on the medicine -- for example, penicillin can cause allergic responses in some people.
"We want to avoid unnecessary exposure to these compounds in the food supply," he said.
Farmers who don't comply with the warning letter can be subject to litigation in which the FDA seeks an injunction, Flynn said. For example, the agency can seek to bar a dairy from shipping milk until its practices improve.
"It is a system where things ratchet up," he said.
Jim Krahn, executive director of the Oregon Dairy Farmers Association, said illegal drug residues are rarely a problem for the industry.
A 2012 survey by FDA found that only about one in 6,000 tanker truck loads of milk across the U.S. tested positive for antibiotic residues, which are correlated with residues in meat, he said.
Even so, the agency wants to reduce such cases even further, Krahn said. "It has been more targeted by regulators."