• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Animal & Veterinary

  • Print
  • Share
  • E-mail


FDA Veterinarian Newsletter May/June 2000 Volume XV, No III

In July 1999, Switzerland reported to the United States that it had found trace levels of diethylstilbestrol (DES) in two samples of U.S. beef. On July 13, the Swiss government published a press release that announced its DES findings in U.S. beef. The press release stated that the amounts detected were at low levels and did not pose an acute health threat.

Laboratory animal studies linked DES to cancer in the early 1970s, and FDA prohibited the use of DES in U.S. food-producing animals in 1979.

The FSIS' National Residue Plan stopped monitoring for DES in 1991, since no positive results or confirmable findings were found for several years. The last positive findings in the early 1970's led to two Department of Justice, FSIS, and FDA investigations and trials, in Wichita, Kansas and Syracuse, New York.

The FDA takes misuse of compounds of public health significance like DES very seriously. The Agency’s Center for Veterinary Medicine (CVM), which has the responsibility to investigate the misuse of drugs in food-producing animals, has carried out an intensive investigation during the past eight months. FDA inspectors have conducted on-farm investigations of animal producers and feedlots delivering animals to the establishment in question. They have investigated bulk drug re-packers, compounding pharmacies, and other points at which illegal diversions of drugs might be uncovered. FDA has thus far found absolutely no evidence of the diversion of DES to use in food animals.

In the meantime, FDA has learned that the Swiss government sent the two positive samples to a European Union (EU) reference laboratory for re-confirmation. The October 14, 1999, report from the EU reference laboratory states "...we must conclude that our analyses do not confirm the presence of DES in the samples submitted for analysis."

The investigation is still ongoing, but to this point, FDA has found no misuse of DES or evidence of its diversion to food-producing animals.