Abstract
<jats:p>The study was aimed at investigating the effect of conditional pathogenic microflora on the development of postpartum endometritis in cows. The research was conducted on 59 cows aged 3–5 years, with an average body weight of 500-550 kg, during the period from February to June. Vaginal and cervical swab samples were collected from cows showing clinical signs of endometritis between May and July 2025. Standard nutrient media, agar plating, and bacterioscopic methods were used for isolation and identification of the microflora. After isolation, the sensitivity of the microorganisms to antibiotics was determined in vitro using the disk diffusion method with doxycycline, amoxicillin, enrofloxacin, colistin sulfate, ciprofloxacin, and sulfamethoxazole/trimethoprim discs. The results showed that in all 15 cows with clinical signs of endometritis after pathological calving, the uterus was contaminated with various conditional pathogenic microflora, predominantly Escherichia coli, Staphylococcus spp., and Streptococcus spp. On the 3rd day postpartum, 46 microbial strains were isolated, while on the 7th day, 26 strains were obtained. The dynamics indicated a decrease in the number of microbial strains after treatment. Microbiological analysis revealed that the microorganisms formed associations, which contributed to the persistence of the inflammatory process and reduced the natural defense of the uterus. According to the study results, when assessing the susceptibility of microorganisms isolated from the uterine microbiota of cows with postpartum endometritis, the inhibition zone diameters for ciprofloxacin, amoxicillin, and enrofloxacin corresponded to a clinically susceptible (S) level.</jats:p>