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Cows on drugs?

Cows on Drugs?

Dairy cows get sick. It's a fact of life. Dairy cows also are worth money. So when they become ill, farmers want to get them back "on line" as quickly as possible.

Most of the time, that means treating the cow with an antibiotic or other drug and then waiting a few days or a week until the residues of the medication "clear" the animal's system.

But not all farmers wait as long as they should. (For some drugs, nobody even knows how long to wait.)

So how can we be certain that drug residues haven't somehow found their way into the container of milk we just bought?

Don't ask the Food and Drug Administration. The FDA's official test for drugs in milk can't detect most of the medications that farmers customarily use--either legally or not--to treat sick cows.

It's clear that potentially harmful drugs (including some carcinogens) could be getting into the milk supply. And it's also clear that nobody's systematically looking for those drugs.

That doesn't mean you should stop drinking milk. But it bothers us that the FDA doesn't know how safe our milk is. What's worse: what it does know, it would rather you didn't.

Testing, Testing. The FDA doesn't routinely test milk. Instead, it has an agreement with the states to do their own testing.

But the only thing the official FDA test (which most states use) is good for is detecting penicillin. The problem is: there are dozens of other drugs that farmers use to nurse sick milk cows back to health.

Are traces of these drugs turning up in milk? The FDA, despite its assurances, doesn't have a clue.

Last winter, we decided to look for ourselves. We used a testing method that is more comprehensive and more sensitive than the one recommended by the FDA. Independently, The Wall Street Journal decided to do the same.

The results became front-page news: residues turned up in four of the 20 milk samples we had collected in the Washington D.C. area, and in 19 of the 50 samples collected by the Journal in ten cities around the country. The drugs that showed up were sulfas, penicillin, streptomycin, and erythromycin.

The FDA Makes Its Moo-ve. Only four days after The Wall Street Journal article broke, the FDA announced that it planned to test milk too.

Great, we thought. The FDA is finally getting serious about drug residues in milk. We should have known better.

"A nationwide survey of milk has found no residues of any antibiotics, including sulfa drugs," the FDA proudly announced a month or so later.

But a close look at the FDA's "clean milk" survey shows that the results weren't so "clean." When the FDA used the same testing method that we did (the Charm II assay), 51 percent of its milk samples showed traces of animal drugs.

So how did it conclude that there were "no residues"?

Simple. The FDA said that the Charm II assay was unreliable. In other words, our "positives" were "false," and our tainted milk was really drug-free.

Milking the FDA for the Truth. But the day after the FDA released its "clean milk" survey, the House Subcommittee on Inter-Governmental Relations and Human Resources held hearings on animal drugs in milk.

Under sharp questioning by subcommittee chairman Ted Weiss of New York, the FDA admitted that it discounted the Charm II results simply because the FDA was unable to confirm those results using other tests--tests that were less sensitive to some drugs and that had never before been used on retail milk.

That's like denying what you see under a microscope because you can't also see it with a magnifying glass. In fact, the tests that the FDA used "do not check for certain drugs picked up by the Charm II assay," testified Joseph Settepani, the FDA chemist who first blew the whistle on the FDA's sloppy regulation of animal drug residues in milk.

"I know," he added, "because I helped coordinate the development of the tests... [The FDA] avoided conceding any problem by prematurely relying on a...method that didn't exist a month ago."

Works Like A Charm. In fact, the test we used--the Charm II assay--is reliable. Several states and a growing number of dairies now use it. (WCBS-TV, the CBS affiliate in New York, also used it to test milk, and also found traces of animal drugs.)

The Charm II test can pick up low levels of seven different families of drugs, although it can't identify specific drugs within those families. That makes it an ideal screening test for drugs in milk. More specific tests are required to tell exactly which drug (and how much of it) is present.

Charm II has been thoroughly tested and approved by the Association of Official Analytical Chemists (AOAC), a professional organization that evaluates test methods. Interestingly, the testing methods the FDA used to show "no drug residues" in milk haven't been approved by anyone.

Just Say "Moo." This isn't the first time the FDA has tried to pull a fast one on the public. In March 1988, nearly three-quarters of the milk samples it tested (in a small survey) contained the drug sulfamethazine, which causes cancer in animals.

How did the FDA and the dairy industry respond to this disturbing discovery? They mounted an "educational campaign" for dairy farmers. ("Just say moo"?) Then the FDA asked the milk industry(!!) to re-test.

According to the FDA, 48 states "participated" in the re-testing, which, to no one's surprise, showed "a dramatic reduction in the illegal use of sulfamethazine in the dairy industry."

But evidence cited by Rep. Weiss revealed that:

* 25 of the 48 states which "participated" in the survey didn't test any milk

* nearly half the samples were collected from just two states--Texas and Maryland--which together produce less than five percent of the nation's milk

* the survey was conducted during the summer months, when cows are healthier and drug use is down.

Allergies from Residues? What's wrong with drugs in milk? After all, they're mostly antibiotics, and doctors give them to us all the time.

To start with, some drugs, including penicillin, streptomycin, tetracycline, and sulfas, may cause allergic reactions in people who drink the milk.

Gerald Guest, director of the FDA's Center for Veterinary Medicine, has admitted that "almost every antimicrobial is potentially dangerous to those individuals sensitive to the substance." (1)

Even very low levels pose a risk of hives, fever, or shortness of breath to some people, although such cases are rare. (2,3) But consider this: Milk is the most common cause of food allergy. In some instances, the offending substance may not be the milk itself, but the residue of some animal drug.

Milk and . . . Carcinogens? Several of the animal drugs that have been found in milk are suspected of being human carcinogens.

The FDA's own studies show that sulfamethazine causes cancer in mice and rats. Residues of the drug in milk and meat could increase slightly the cancer risk for humans.

Other sulfa drugs might also prove to be cancer-causers, but most of them haven't been tested. Because of the cancer risk, the FDA has said it intends to ban the use of sulfamethazine in animals. It also ought to live up to its 1980 pledge to consider banning all sulfa drugs, if it bans sulfamethazine. (4)

Nitrofurazone is another antibiotic that FDA officials suspect is widely used to treat milk cows, although it isn't approved for that use. According to the National Toxicology Program, there is "clear evidence" that nitrofurazone causes cancer in animals.

But a 14-year-old FDA proposal to ban the drug has yet to be finalized. (5) As far as we know, no one is testing for nitrofurazone. (The test we used can't detect it).

Udder Concerns. Some drugs that have been found in milk could cause non-cancerous toxic effects.

For instance, chloramphenicol, a powerful antibiotic, and phenylbutazone, an anti-inflammatory drug, have been linked to aplastic anemia, an irreversible and usually fatal disease that strikes the bone marrow.

Chloramphenicol is banned from use in food-producing animals, yet traces of the drug have been detected in milk. (6) In 1988, supplies of chloramphenicol were found on five of 78 Colorado dairy farms inspected by state authorities. Fortunately, none of the recent tests detected any in milk.

Rep. Weiss has obtained from the FDA a list of 30 unapproved drugs that the agency suspects are often used in milk cows. Yet the FDA has no idea whether these drugs are getting into milk, since its official test only detects 2 of the 30.

"Until milk can be examined for residues from these additional drugs, no one can claim with any confidence that our milk supply is safe, says FDA whistleblower Joseph Settepani.

Irresistible Bacteria? Drug residues may pose problems for people who drink milk. But there's another problem--this one even for people who don't.

As the use of antibiotic drugs increases, the bacteria they are designed to fight eventually develop a resistance to the drugs. If you happen to become infected with one of these drug-resistant bacteria, the antibiotics your doctor gives you may not be effective.

Our drugs should come from a doctor, not from old Bessie.

Ruminating on Milk Safety. So what can we do about residues of animal drugs in milk? Don't hold your breath waiting for the FDA to take action.

But don't cut back on drinking milk, either. That could be risky if you're a nursing or soon-to-be mother, or if you're an infant. (If you're an infant and have read this far, please have your mother send us your resume.)

The amounts of animal drugs found in milk are too small to justify a recommendation to stop drinking. But the risk is unnecessary. That's why you should demand that the FDA (Commissioner, FDA, 5600 Fishers Lane, Rockville, Maryland 20857):

* start using tests that are capable of detecting low levels of a wide range of drugs

* ban the use of cancer-causing drugs like sulfas and nitrofurans

* phase-out the FDA's "extra-label drug use policy," which allows veterinarians to prescribe drugs for dairy cows even though the medications are approved only for use in other animals. (Rep. Weiss calls the policy "illegal.")

* require drug manufacturers to develop inexpensive and rapid screening tests for all the animal drugs they produce.

(1) FDA Veterin. I (II): 1986.

(2) AMA Arch. Derm. 19: 1, 1959.

(3) Ann. Allergy 53: 243, 1984.

(4) Fed. Reg. 45: 63930, 1980.

(5) Fed. Reg. 41: 34899, 1976.

(6) J. Food Protect. 51: 8 & 632, 1988.
COPYRIGHT 1990 Center for Science in the Public Interest
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1990, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Title Annotation:antibiotic residues in milk
Author:Lefferts, Lisa Y.
Publication:Nutrition Action Healthletter
Date:Apr 1, 1990
Words:1763
Previous Article:Pack it right.
Next Article:Let them eat Entenmann's.
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