BackgroundDisease prevention and control is a significant part in the ex-situ conservation of the endangered red panda (Ailurus fulgens), with bacterial infection being one of the most important health threats to the captive population. To date, studies about the Escherichia coli infection in the red panda are scarce. This study was conducted to determine the cause of death of a captive red panda through clinical symptoms, complete blood count, biochemical analysis, pathological diagnosis and bacterial whole genome sequencing.Case presentationOne 1.5 year old captive female red panda (Ailurus fulgens) was lethargic and anoretic. She was moved to the quarantine area for daily treatment of oral cefpodoxime proxetil 50mg. During this period, she did not eat or defecate, and died at 15:00 on November 21. Clinical examination revealed the values of neutrophils; alanine aminotransferase (ALT), aspartate aminotransferase (AST) and blood urea nitrogen (BUN) were significantly higher. Histological analysis demonstrated major pathological damage in the kidneys, liver and lungs, characterized by hyperemia, parenchymal cell degeneration and necrosis and inflammatory cell infiltration which was predominantly neutrophilic. A bacterial strain confirmed as Escherichia coli was isolated from the red panda post mortem. Whole-genome sequencing of the E. coli showed the complete sequences of the chromosome was 4.99 Mbp. PapA, PapG, OmpA, OmpU and other virulence factors were specific to Uropathogenic Escherichia coli (UPEC). Among the virulence factors, P pili, type I pili and related factors of the iron uptake system were associated with nephrotoxicity. ConclusionThe red panda died of bacterial infection caused by an Uropathogenic strain of Escherichia coli. The pathogenic mechanisms of the strain are closely related to the expression of specific virulence genes.