Unilateral septic neutrophilic lymphadenitis caused by Yersinia pseudotuberculosis in two dogs and one cat in Stockholm during a 16‐day period in November 2025

Abstract Two dogs and one cat with unilateral septic neutrophilic lymphadenitis caused by Yersinia pseudotuberculosis were presented, diagnosed and treated at AniCura Referral Animal Hospital Bagarmossen in Stockholm, Sweden, during a 16‐day period in November 2025. The animals presented with acute onset of pyrexia, decreased appetite and lymphadenopathy. All three cases responded rapidly to ampicillin or amoxicillin and recovered completely. The cause of the infection is unknown, but it could be the outdoor environment. Y. pseudotuberculosis is a zoonotic bacterium present in many wild animals. It can grow at low temperatures.