Salmonellosis also poses a respiratory threat to pigs, not just an enteric threat.

Uncontrolled, S. choleraesuis bacteria can escape the boundaries of the intestinal tract and travel throughout the body of pigs, lodging in multiple body organs and causing a potentially fatal septicemia. Signs of septicemic salmonellosis include lethargy, loss of appetite, mild cough, difficult breathing, fever, purplish extremities (ears, legs, etc.), and possibly diarrhea after 3 to 4 days.

Furthermore, the bacteria can invade the lungs, triggering severe respiratory disease and potentially contributing to a PRDC outbreak.

Producers intent on optimizing their productivity must include Salmonella-control measures in their overall herd health strategy.

Salmonella are gram-negative bacteria that live primarily in the intestinal tracts of animals. Although over 2400 different types of Salmonella are thought to exist, Salmonella choleraesuis and Salmonella typhimurium are most commonly isolated from swine. In addition, humans are also at risk from the bacteria via contamination of market products, since Salmonella is the most common food-borne illness in the world.

Enteric salmonellosis occurs mainly in weaned pigs, causing colitis. Bacterial shedding from infected “carrier” pigs, and contaminated production environments, are the main sources of S. choleraesuis infection. Enterocolitis usually occurs in pigs from weaning to 4 months of age, with the first sign often a yellowish diarrhea that may persist off and on for weeks. Though most pigs survive the enterocolitis, they can remain carriers and bacterial shedders for months after recovery.

Treatment of salmonellosis involves reducing disease symptoms, bacterial shedding, contamination of the production environment, and contamination of pork meat at slaughter. These goals can be difficult to accomplish because Salmonella organisms can inhabit biological niches (tissues such as tonsils or lymph nodes) that are often difficult to reach with antibiotics. Proper sanitation and prevention measures (such as feed-grade antimicrobials and vaccination) are the best practices to minimize salmonellosis and Salmonella contamination of pork products.