Abstract
BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales can be disseminated within households, including sharing of strains between people and pets, posing a public health risk. This case report demonstrates that household dissemination can also lead to antimicrobial-resistant infections in other pets in the household. CASE SUMMARY: A 14-year-old domestic shorthair cat with a subcutaneous ureteral bypass system was diagnosed with a urinary tract infection caused by Escherichia coli ST162 with CTX-M-14 ESBL. The cat was successfully treated. Seven months later, a 16-year-old mixed-breed dog in the same household was diagnosed with cholangiohepatitis caused by E. coli ST162 with CTX-M-14. Genomic comparison of the feline urine and canine bile isolates showed that they were highly genetically similar, despite months passing between resolution of the cat's infection and the beginning of the dog's clinical signs. CONCLUSION: Dissemination of ESBL-producing E. coli to other pets, as well as to people, is possible when an animal in the household has an infection. In this case, cohabiting animals both developed clinical infections, highlighting the need for guidance to prevent pet-to-pet spread of antimicrobial-resistant pathogens.