The Danish Ministry of Food, Agriculture and Fisheries funds a monitoring system based on drug usage information collected at the herd level: VETSTAT. VETSTAT is constructed as a relational database and data originates from three sources: pharmacies, veterinarians and feed mills. All administration of drugs for use in animal production is reported on a monthly basis. Pharmacies provided 95% of the total weight antimicrobial compounds used in Denmark in 2001. More than 80% of the antimicrobial compounds reported by pharmacies were sold on prescription to end-users (owners) and included information on animal species, age-group and diagnostic grouping; >90% of the total amount of antimicrobials sold on prescription was used for pigs. In 2001, sales of 96,500 kg of antimicrobials were reported.