Further diagnostics may be applied by biopsy, taking a small sample of uterine tissue for histological examination. The endometrial biopsy will show structural changes to the uterine wall and lining, often revealing evidence of more chronic or deep-seated endometritis. Treatment of mares with bacterial infection is best accomplished by lavage therapy and subsequent infusion of broad-spectrum antibiotics. Susceptibility trials can determine the selection of the specific antibiotic for appropriate treatment. In many cases, optimal treatment is accomplished by identifying the organism present in the culture growth and using the appropriate antibiotic to kill that bug.
Uterine lavage serves to remove the inflammatory debris and stimulate uterine contractility.
In addition, uterine lavage functions as a mechanical irritation of the endometrium and stimulates recruitment of fresh neutrophils to help combat the infection. Oxytocin is the pharmaceutical of choice for promoting uterine contraction, aiding the uterus in the elimination of fluids. Use of oxytocin is best prior to and up to 2 days after ovulation, while the cervix is still soft enough for the fluids to be expelled. Mares with clearance problems are routinely managed by using oxytocin after insemination, leaving at least 4 hours for the semen to travel to the oviducts before treatment begins. Treatment of endometritis is ideally done the day before or the day of ovulation.