Salmonella enterica serovar Typhimurium isolated from the urine of a dog undergoing treatment for immune-mediated polyarthritis

INTRODUCTION: In people, Salmonella is a common agent of gastroenteritis, but it can also cause extraintestinal disease such as urinary tract infections. In addition, Salmonella is often linked to the post-infection development of reactive arthritis. In canines, cases that document extraintestinal Salmonella infections or diseases similar to reactive arthritis have not been thoroughly described. CASE PRESENTATION: A case of a 5-year-old German shepherd dog with Salmonella bacteriuria during treatment for immune-mediated polyarthritis (IMPA) is described. The patient first suffered from a 3 month period of diarrhoea and presented for evaluation of a 2 month history of shifting-leg lameness. A diagnosis of IMPA was made based on cytological examination and negative synovial fluid culture. Treatment with immunosuppressive doses of prednisone lead to clinical resolution of lameness, but on a recheck abnormal urine was noted. Salmonella enterica serovar Typhimurium was isolated using standard culture methods. The patient was treated with enrofloxacin to control the bacteriuria. CONCLUSION: This case report is, to the best of our knowledge, the first to describe Salmonella bacteriuria in a dog and suggests that Salmonella infection may be a potential inciting factor for IMPA.