This report describes two cases of Salmonella mesenteric lymphadenitis leading to septic peritonitis in two young dogs. The cases were similar in presentation, diagnosis, treatment, and length of hospitalization. Both cases presented with clinical signs of vomiting, abdominal pain, and fever and were treated successfully via surgical debridement, omentalization, and antibiotic therapy. Both cases grew multi-drug resistant Salmonella spp. with resistance to ampicillin sulbactam, which is a common empiric antibiotic choice for cases of canine septic peritonitis. In both cases, the source of Salmonella is proposed to be the raw diet that preceded the septic peritonitis diagnosis. While Salmonella mesenteric lymphadenitis has been reported in humans and pigs, to the authors' knowledge, this is the first report of Salmonella mesenteric lymphadenitis in dogs.