Endometritis is a major cause for impaired fertility in mares. The objectives of this study were to collect information on diagnostic and treatment practices performed by veterinarians and to investigate possible effects of professional experience, caseload, and geographical location on the practitioners' management of endometritis cases. For this purpose, equine practitioners ( n = 680) were asked to fill out an online survey (34 questions). The online survey yielded 117 responses by veterinarians practicing in all parts of Germany. Most respondents came from Lower Saxony and managed <20 mares per year. For the diagnosis of chronic infectious endometritis, uterine sampling for microbiological examination was performed manually with a swab by the majority of practitioners whereas only few used the speculum technique. The incidence of antibiotic resistant pathogens was reported to be <5% by almost all respondents. Most practitioners relied on systemic antibiotic treatment with trimethoprim-sulfadiazine. Only occasionally veterinarians used intrauterine antibiotic therapy. Uterine lavages were performed routinely by almost half of the respondents in case of positive uterine cultures, mostly with 0.9% saline solution. Irritant solutions (e.g., iodine, chlorhexidine, kerosene) were used less often. Collection of an endometrial culture after completion of the treatment was common practice. While only a very limited association of the geographical location of practitioner (e.g., on selection of mares for endometrial culture, p < 0.05) was observed, the number of managed mares affected the answers notably (e.g., for use of irritating intrauterine treatment, p < 0.05). The management of persistent breeding induced endometritis (PBIE) was influenced by the number of managed mares (e.g., for use of oxytocin, p < 0.05) and 29.6% of respondents administered antibiotics as part of their PBIE management. In summary, treatment strategies in the field vary considerably and include also non-evidence-based methods, but most German practitioners apply the recommended suitable treatments. Following the guidelines for antibiotic usage, most veterinarians administer antibiotics dependent on endometrial culture results but do not use cytology, low-volume lavage, or biopsy routinely. Antibiotic resistant uterine pathogens are reported to be isolated infrequently and equine practitioners prefer systemic to local antibiotic treatment of endometritis.