Assessment of the association of ESBL-producing Escherichia coli with clinical severity of chronic enteropathy in dogs in Brazil.

Canine chronic enteropathy (CCE) includes persistent gastrointestinal disorders that may be associated with antimicrobial-resistant bacteria. We evaluated the correlation between clinical severity of CCE and the presence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in dogs with CCE. We assessed 64 dogs using the canine chronic enteropathy clinical activity index (CCECAI) and analyzed rectal swabs for E. coli and ESBL detection. E. coli was isolated from 28 dogs (44%), with ESBL-positive strains identified in 8 (12%). All ESBL-positive cases had severe clinical scores (CCECAI ≥ 9), with a strong association between ESBL phenotype and disease severity (p < 0.001). These multidrug-resistant isolates remained susceptible to imipenem. Histologic findings confirmed marked intestinal inflammation in ESBL-positive cases. No age or sex association was observed. Our results emphasize the clinical relevance of ESBL-producing E. coli in severe CCE and support the inclusion of microbial profiling in diagnostic and therapeutic strategies.