A comparison of agents for inducing parturition in mares in the pre-viable and premature periods of gestation.

The research explores efficient protocols for inducing labor in mares during the pre-viable and premature stages of pregnancy, with the most effective found to be two injections of fluprostenol with an possible follow up of oxytocin.

Objective and Methodology

• The primary goal of the research was to identify the most effective method of inducing labor in pregnant mares, in both the pre-viable and premature gestation stages.
• Several regimens of the hormones prostaglandins and oxytocin were tested. Prostaglandins were administered either alone, or followed by doses of oxytocin.

Findings

• The most successful regimen was found to be two doses of 500 micrograms of fluprostenol, a type of prostaglandin, given intramuscularly at two-hour intervals.
• If necessary, this course of treatment could be followed by 10-20 international units (i.u.) of oxytocin, another hormone capable of inducing labor. This second hormone is administered intravenously in 5 i.u. increments every 15-20 minutes.
• The research showed that peak concentrations of a metabolite of prostaglandin (PGFM) in response to the inducing agents were generally seen in relation to delivery on the 320th day of gestation, but not prior.

Radiolabelled Study of Fluprostenol Distribution

• A part of the research involved tracking the distribution of fluprostenol – a synthetic analogue of prostaglandin – within the biological system of the mares.
• To do this, a radioactive carbon-14 labelled version of fluprostenol was used, and its presence was monitored across several bodily tissues and fluids, including the placenta, amnion, allantoic and amniotic fluid, as well as in foal plasma and liver.

Significance

• The findings of this study could have significant impact in veterinary medicine, specifically in the field of equine reproduction.
• Understanding the distribution of labor-inducing agents can provide insights that can help create more effective and reliable protocols for induced labor in mares.