This lecture will review the clinical management of extensively resistant gram-negative infections in companion animals.  The primary two type of pathogens will include extended-spectrum β-lactamase producing (ESBLs) and carbapenem-resistant Enterobacterales (CRE).  ESBLs have been common for many years, but recent reports suggest that CRE have recently emerged as clinical pathogens, particularly in tertiary referral centers.   Topics covered will include background information about pathogens, new antibiotic susceptibility testing changes that impact treatment of many infections, treatment with commonly utilized antibiotics, and treatment with less-common antibiotics.