Use of a low-volume uterine flush for microbiologic and cytologic examination of the mare's endometrium

A guarded uterine swab and a low-volume uterine flush were compared for microbiologic and cytologic examination of the endometrium of young, normal mares (n = 24) and aged, subfertile mares (n = 27). Mares from each group had clitoral sinus swabs, guarded endometrial swabs (X2), uterine flushes and endometrial biopsy samples taken for microbiologic, cytologic and histologic examination. The guarded swab technique yielded significantly fewer (P < 0.05) microbiologic cultures with pathogenic microorganisms than the flush technique for both normal mares ( 0 24 vs 6 24) and subfertile mares ( 4 27 vs 14 27). The swab technique also yielded significantly fewer (P < 0.05) endometrial smears with cytologic evidence of inflammation than the flush technique for subfertile mares ( 12 27 vs 20 27); however, there was no significant difference (P > 0.1) for the two techniques for cytologic results in normal mares ( 3 24 vs 7 24). Ureaplasma spp. were isolated from the uterine flushes ( 3 27) and clitoral sinus swabs ( 6 27) from subfertile mares. Mycoplasma spp. were isolated from the uterine flush from one subfertile mare and clitoral sinus swab from another subfertile mare. Significantly fewer (P < 0.01) normal than subfertile mares had histologic evidence of inflammation in endometrial tissue sections ( 5 24 vs 25 27). Based on microbiologic and cytologic results, the low-volume uterine flush appeared superior to the guarded endometrial swab for the diagnosis of endometritis in mares.