Microbial Profile of Post-Breeding Endometritis in Arabian Mares from Al-Hira District, Iraq

Background: Post-breeding endometritis in Arabian mares represents a significant reproductive challenge, necessitating proper pathogen identification and antimicrobial susceptibility determination. Objectives: To investigate the prevalence of intrauterine pathogens and their antimicrobial susceptibility patterns in Arabian mares with post-breeding endometritis. Methods: Seventeen Arabian mares were examined clinically and ultrasonographically. Uterine swabs were collected for bacterial isolation and antimicrobial susceptibility testing. Results: Clinical endometritis was detected in 29.4% of mares. Ultrasonographic examination revealed varying degrees of uterine wall thickness: slight (58.82%), moderate (11.76%), and severe (29.41%). E. coli was the predominant pathogen (76.47%), followed by Streptococcus spp. (11.76%), with mixed infections in 11.76% of cases. Both pathogens showed high resistance to several antimicrobials but demonstrated significant susceptibility to β-lactam antibiotics and selected fluoroquinolones. Conclusions: E. coli was the primary pathogen associated with post-breeding endometritis in Arabian mares. The high antimicrobial resistance patterns observed emphasize the importance of culture-based treatment selection. β-lactam antibiotics showed promising efficacy against both isolated pathogens.