Equine pyometra: A case report

Summary A 19-year-old Thoroughbred mare was referred to the Veterinary Teaching Hospital at the University of Georgia College of Veterinary Medicine. The mare had a history of being barren for the previous 3 years, despite repeated breedings. She had foals prior to the more recent bout of infertility. She had not returned to heat this season after being bred. She was referred for ultrasonographic determination of pregnancy, as the referring veterinarian had palpated an enlarged uterus but was not convinced she had settled to this season's breeding. Upon examination it was noted that the mare had very poor perineal conformation and was a “urine pooler.” Rectal examination of the tubular reproductive tract revealed the uterus was enlarged, fluid filled, and quite “doughy” in consistency. The mare's cervix was closed and tight. Ultrasonography was performed. This revealed an enlarged uterus (Figure 1) which was filled with fluid. The fluid was echogenic and gave the appearance of ground glass on ultrasound. No fetus could be seen. A corpus luteum (CI) was present on the left ovary (Figure 2) as seen on ultrasonography. A diagnosis of pyometra was made, and the mare was given PGF 2α to lyse the CI. Within 4 days of the PGF 2α injection, the cervix began to open. The mare was treated with 5mg of estradiol cypionate to hasten cervical dilation and the uterus was lavaged. The uterus was biopsied to determine ability of the endometrium to support a fetus.