Veterinary medicines are used for the treatment or prevention of diseases in livestock. The administration of medicinal feed additives to promote growth or enhance performance has been prohibited in Switzerland since 1999.

Antibiotics are the largest group of medicinal products used in this sector. Depending on the type of antibiotic, the active ingredient will be excreted either unchanged or in a biochemically modified form. These substances are thus released into the environment via manure and slurry or directly on pastureland. The regulations concerning the management of farmyard fertilizers are therefore also important with regard to veterinary medicines.

The behaviour of excreted veterinary medicines and their metabolites in the environment varies widely. Unresolved questions are being studied in a number of research programmes:

While some substances are strongly bound to soil particles and can be detected in the soil for several weeks, others are water-soluble and are rapidly leached out into groundwater or surface waters.

The likelihood of antibiotics entering waterbodies is high in the case of sulphonamides, medium for tetracyclines and fluoroquinolones, and low for penicillins and macrolides. Substances that are not washed out can accumulate in the soil.

Measures in the agricultural sector

To reduce the need for the use of veterinary medicines, comprehensive preventive measures are to be taken, particularly with regard to feeding and housing.

Farmers are required to keep records of all treatments involving veterinary medicines. Antibiotics are only to be prescribed by vets.