Indications and patterns of therapeutic use of antimicrobial agents in the Danish pig production from 2002 to 2008

This study describes trends in the use and indications for prescriptions of antimicrobial agents in the Danish pig production in the period between 2002 and 2008 and is the first description of a complete prescription pattern for one animal species in an entire country. Data on all prescription for pigs in Denmark were retrieved from the VetStat database. Antimicrobial use was measured in defined animal daily doses (ADD) for the specific age-group and in ADDkg as a measure of amounts used. According to the results of the ADDkg data, 26% of all antimicrobials were prescribed for sows, 38% for weaner pigs, and 33% for finisher pigs. In weaner and finisher pigs, gastrointestinal infections accounted for 74-83% and 56-65% of the use, while respiratory infections accounted for 9-17% and 18-24%, respectively. From 2002 to 2008, prescription for respiratory disease increased by 145% for sows/piglets, by 141% for weaning pigs, and by 81% for finisher pig. The most commonly used class of antibiotics was tetracycline for all age-groups, replacing the previously used macrolide /lincosamide group. The use of pleuromutilin increased in 2008 to the level of macrolides. In sow /piglets, the second most used class was penicillins. The switch in choice of antimicrobial classes prescribed seems to be related primarily to changes in the price of the drugs.