Study on bacterial isolation, antibiogram and therapeutic management of canine otitis externa

Abstract

Canine otitis externa (COE) is a multifactorial condition characterized by acute or chronic inflammation of the external ear, significantly impacting affected dogs and posing diagnostic and therapeutic challenges. The present study analyzed 92 clinical cases from the Junagadh region, focusing on bacterial etiology, incidence patterns and antimicrobial susceptibility profiles. Staphylococcus spp. was identified as the predominant pathogen (48.18%, 53/110), followed by Pseudomonas spp. (11.81%, 13/110) and Proteus mirabilis (10.91%, 12/110) isolates, respectively. Higher incidence was observed in non-descript breeds (33.70%, 31/92), male dogs (57.61%, 53/92) and dogs aged 6-10 years (55.43%, 51/92). Antimicrobial sensitivity testing (AST) demonstrated that Staphylococcus spp. was highly susceptible to amoxicillin-clavulanic acid (92.45%), gentamicin (86.79%) and chloramphenicol (83.01%) but exhibited resistance to penicillin-G (81.13%). Pseudomonas spp. showed the greatest sensitivity to gentamicin (84.61%) and amoxicillin-clavulanic acid (76.92%), while Proteus spp. was most sensitive to chloramphenicol and doxycycline (91.67%). These results emphasize the need for AST-guided therapy to mitigate antimicrobial resistance and improve treatment efficacy. These findings underscore the importance of targeted diagnostic approaches and precise antimicrobial therapies to enhance otitis externa management and improve canine health outcomes.