The primary cause of pyometra of the mare is intraluminal cervical adhesions resulting from trauma, such as that sustained during parturition or from manipulating the cervix while administering intrauterine therapy, performing artificial insemination,or flushing embryos. Adhesions inhibit escape of debris and bacteria from the uterus, leading to pyometra. Mares are treated for pyometra by disrupting cervical adhesions, lavaging the uterus, administering intrauterine and systemic antimicrobial therapy, and administering an ecbolic drug, such as oxytocin or a prostaglandin analog, to encourage expulsion of uterine contents. Ovariohysterectomy has been the only option for treatment when pyometra becomes recurrent. Another, more economical and less difficult treatment of mares for recurring pyometra, recently reported by clinicians at Texas A&M University, is cervical wedge resection.1 This treatment is associated with fewer complications than is treatment by ovariohysterectomy, and even though a mareis incapable of carrying a foal to term after undergoing a cervical wedge resection, this treatment may preserve the mare's ability to produce foals by assisted reproductive techniques, such as embryo transfer. Cervical wedge resection is performed withthe mare sedated after administering epidural anesthesia. The perineum is prepared for surgery, and a speculum is inserted into the vagina.1 A stay suture is placed at the right and the left dorsolateral aspects of the external os of the cervix, adjacent to the proposed site of resection, and the cervix is retracted caudally by placing tension on the stay sutures. A triangular section of the dorsal aspect of the cervix is excised between the stay sutures using a long scissor. The section of tissue is 3to 4 cm wide at its base, and its apex points cranially and extends to the internal os. Care must be taken to avoid penetrating the peritoneal cavity during dissection. An ointment containing a corticosteroid is applied daily for 2 weeks to the incisededges of the cervix. Intermittent uterine lavage or imbricating the mesometria (i.e., uteropexy) to position the uterus horizontally may also be required if the uterus is positioned vertically, inhibiting evacuation of uterine contents.
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