Since the mid-1990’s, Salmonella Typhimurium has been the predominant serotype of Salmonella enterica identified in diagnostic samples as a significant cause of clinical disease in swine. However, over the past 5 years, identification of Salmonella Typhimurium in samples from diseased swine has decreased substantially while identification of the Salmonella I 4,[5],12:i:- serotype has concurrently increased.