Resolution of two cases of ovarian abscesses in mares subjected to ovum pick up

Background Currently, for in vitro embryo production in live mares, immature oocytes are retrieved by transvaginal follicular aspiration or ovum pick up (OPU). Occasionally, ovarian abscesses have been described after OPU, but no current consensus exists on how to treat this condition. Objectives To describe diagnosis and successful treatment of ovarian abscesses in two mares subjected to OPU. Study design Case report. Methods Case records were reviewed and summarised. Results In the first case, a pony mare showed tachypnoea, tachycardia, high temperature, leukocytosis, left hindlimb lameness and slight increase in concentration of serum amyloid A. Ultrasonography revealed an increase in the size of the left ovary and two well defined structures suggestive of ovarian abscess. A left ovariectomy by standing laparoscopy was the treatment of choice: the diagnosis was confirmed, and bacterial culture produced heavy growth of Streptococcus equi Zooepidemicus. In the second mare, an abnormal structure was observed in the left ovary in a routine transrectal ultrasonographic exam in the absence of any clinical signs or abnormal blood parameters. A medical approach was chosen and a sample of the purulent material was aspirated with a transvaginal ultrasound‐guided approach. The sample yielded a heavy growth of Streptococcus equi Zooepidemicus after culture. Treatment was initiated with rifampicin and trimethoprim—sulfadiazine based on the antibiogram results and the abscess completely resolved after 40 days. Main limitations Limited to two cases. Conclusions Ovarian abscesses in mares can be successfully treated both surgically and medically.