Technical Abstract: Salmonella enterica serotype Typhimurium phagetype DT104 is a multiple antibiotic resistant pathogen that has been purported to be more pathogenic than other Salmonella. In this study, we evaluated the possibility that DT104 is the causative agent of veal calf abomasitis observed in four independent outbreaks of salmonellosis. This study was undertaken to determine if the outbreaks might be due to hypervirulent Salmonella enterica serotype Typhimurium phagetype DT104 since Salmonella does not usually cause abomasitis. Tissues and fluids from these calves were subjected to bacteriologic culture and polymerase chain reaction assays. Pure Salmonella cultures were then used in tissue culture invasion assays and bovine challenge experiments. Multiple antibiotic resistant Salmonella enterica serotype Typhimurium phagetype DT104 was identified as the causative agent of abomasitis in calves. Thus, abomasitis is a potential indicator of infection with multiple antibiotic resistant Salmonella enterica serotype Typhimurium phagetype DT104 and adds credence to the potential hypervirulence of this pathogen.