Salmonellosis is a disease affecting most livestock production systems worldwide. As a zoonosis the disease has assumed increasing importance in recent years.

Salmonella infections in swine spread very quickly following oral exposure. Organisms multiply rapidly in the intestine, before spreading to many internal organs, resulting in an overall reduction in pig performance

Salmonella typhimurium also has a greater potential to develop multiple drug resistance and the presence of such isolates has increased dramatically over the years, posing a serious health risk for both pigs and humans.

Salmonella typhimurium is the most common salmonella serotype isolated from many European pig herds. Infection is usually sub-clinical and many animals go on to become carriers resulting in a potentially serious problem during processing at the abattoir.