As most cases of listeriosis are associated with feeding soil-contaminated, fermented or poor quality silage with high pH-values, feeding good quality silage is the most commonly recommended method of prevention in regard to listeriosis. Making sure that silage is not contaminated with excessive soil during silage making and removing contaminated or fermented parts of the silage as they are detected are likely to reduce the risk for listerial infections.
Feeding fattening stock with in-feed antibiotics on a prophylactic basis is not acceptable under organic standards.
Once an outbreak or a sporadic case has occurred and been diagnosed, the veterinarian might want to consider metaphylactic treatment of in-contact animals with suitable antibiotics. This is acceptable under organic standards as the welfare implications of further cases would be serious.