Deep Pyoderma Caused by <i>Serratia marcescens</i> in a Border Collie in China

This case report highlights Serratia marcescens as a causative agent of deep pyoderma in a Border Collie which presented with multiple erythematous lesions on the abdomen and back. The diagnosis of deep pyoderma was confirmed through clinical evaluation and bacterial identification. This case is the first reported instance of S. marcescens infection in a dog in China, and it was successfully managed with targeted antibiotic therapy.