Magnesium sulfate intrauterine therapy in the mare

A study was conducted to investigate the effect of magnesium sulfate solution on the equine endometrium using 7 treatment mares and 3 control mares. Treatment mares were infused with 128 grams of magnesium sulfate in one liter of 0.9% sodium chloride, while control mares were infused with one liter of 0.9% sodium chloride. Reproductive examinations, including palpation and ultrasound examination per rectum of internal genitalia, vaginoscopy, uterine culture, uterine cytology, endometrial biopsy, and hysteroscopy, were performed 12 days prior to infusion and days 1, 7 and 21 after infusion. Serum magnesium concentrations were assessed at 0, 1, 2, 4, 6, and 12 hours post-infusion. The only statistically significant findings in assessed reproductive parameters was a more cloudy vaginal discharge and a higher biopsy score in control mares on day 1 post-infusion. These findings were not present at the day 7 or 21 observation periods. This study demonstrates that intrauterine magnesium sulfate, used at the concentration described, did not result in harmful effects detectable by the parameters evaluated. It should be noted that assessment of the effect of magnesium sulfate on specific uterine pathologies or fertility was not made.