Six mares had ovariohysterectomy performed for chronic pyometra associated with cervical abnormalities, uterine neoplasia, or removal of a macerated fetus. Ovariohysterectomy was performed through a ventral midline incision with access to the ovarian and uterine vessels aided by traction on the uterus and retraction of abdominal viscera. Abdominal pain, the most common complication after surgery, occurred in four mares but resolved within 36 hours. Peritonitis occurred in two mares; one mare was subsequently euthanatized. Other complications that resolved with treatment included infection of the uterine stump (two mares), abdominal hemorrhage (one mare), diarrhea (one mare), and incisional infection (one mare). Complications after surgery can be reduced by removing as much of the uterus as possible, minimizing peritoneal contamination with uterine contents, and providing a secure closure of the caudal reproductive tract.

No abstract

The effect of inhibition of cyclooxygenase activity on the hemodynamic response to exertion was examined in 6 horses. Rates of O2 consumption and CO2 production and carotid, pulmonary arterial, and right atrial pressures were measured while the horses performed a standardized exercise test on a treadmill after treatment with phenylbutazone or a placebo. Phenylbutazone (8.8 mg/kg p.o. for 2 days and 4.4 mg/kg i.v. 60 min before exertion) abolished the exertion-induced increases in plasma 6-ketoprostaglandin F1 alpha and thromboxane B2 concentrations, confirming inhibition of cyclooxygenase activity. Phenylbutazone treatment resulted in significantly (P < 0.05) higher heart rates and right atrial pressures during exertion than did treatment with placebo, which may have been due to increased myocardial sensitivity to sympathetic stimulation and/or decreased venous compliance. There was not a detectable effect of phenylbutazone on carotid or pulmonary arterial pressures, O2 consumption, CO2 production, or blood lactate concentration. Changes in plasma volume during exertion were not influenced by phenylbutazone. These results demonstrate that cyclooxygenase products likely mediate or modulate some of the systemic hemodynamic responses to exertion in horses.