Eliminating swine dysentery from selected herds.

In attempts to eliminate swine dysentery from a herd, the total cost of nitroimidazole medication in the water can be estimated at 16/gal over 3-4 weeks and for carbadox in the feed at 70/100 lb over 6-8 weeks. Use of dimetridazole or ipronidazole in the water for 3-4 weeks or carbadox in the feed for 6-8 weeks eliminates Treponema hyodysenteriae from the porcine gut. A 30-day (10 weeks with carbadox) preslaughter withdrawal time should be provided. Impervious surfaces should be thoroughly sanitized, while permeable surfaces and lots should be cleaned, dried and aired well for 2-3 weeks in warm, dry weather and for at least 60 days in cool, damp weather. Animal vectors and fomites must be controlled. Isolation of new breeding stock for 3-4 weeks helps prevent recontamination. While elimination of swine dysentery is not practical in many herds because of poor facilities or lack of producer commitment, a properly designed program can result in economic benefits.