In the Netherlands about 0.5 percent of all animals slaughtered are examined for traces of antibiotics, using the new Dutch kidney test. This test measures an effect, such as the inhibition of bacterial growth. The test can demonstrate that bacteria growth inhibitors are present in a sample, but can not identify the specific chemical responsible for the inhibition. The proportion of animals that test positive with this test has been stable for some years at about 0.2 percent.
Kidney test
Of the 300 samples of meat taken (100 fattening calves and 200 pigs), the sulphonamide sulphadiazine was found in only one at a concentration exceeding the MRL. Xylazine, a sedative, was found once in the kidney of a pig, although the level was below the MRL. In the other 101 kidney samples that were tested for the presence of sedatives and ß-agonists these substances were not demonstrable. In the liver of one horse the level of the endoparasiticide ivermectin was higher than the MRL.
In addition, in a number of other liver samples, residues of thiabendazole, levamisole or ivermectin were found; the levels in these samples were lower than the MRL. The additive carbadox (and the metabolite desoxycarbadox) were not found in the 302 samples of pig kidney. The forbidden veterinary drugs listed in appendix IV of Regulation 2377/90/EEC, the nitrofuranes, dapsone and chloramphenicol, were also not found in 1997.