Cortisol, progesterone, 17αOHprogesterone, and pregnenolone in foals born from mare’s hormone-treated for experimentally induced ascending placentitis.

The study investigates the levels of four different hormones in newborn foals born from mares with experimentally induced ascending placentitis. Different treatment combinations have been used with the aim of evaluating their impact on the foals’ hormone levels and survival rates.

Research Objectives

• The main aim of this research was to gauge the levels of four hormones – cortisol, progesterone, 17αOHprogesterone, and pregnenolone – in foals born from mares treated with various combinations for ascending placentitis.
• The study also sought to track survival rates in the first week of life and categorize foals as either high-risk or low-risk based on clinical and hematologic findings.

Research Methodology

• A total of 46 pregnant mares and their foals were included in the study. The mares were split into various groups, based on the treatment received – a healthy group (Control), TMS+FM, TMS+FM+ALT, TMS+FM+ALT+ECP, TMS+FM+ECP, and a no-treatment group.
• The treatment began two days after placentitis was experimentally induced using Streptococcus zooepidemicus.
• The hormone levels in the foals were measured immediately after birth (0 hrs), at 12, 24, and 48 hrs, and seven days after birth. Collectively, the hormone levels of 31 out of the 46 foals were determined through immunoassays.

Findings and Conclusion

• Findings showed that the serum cortisol concentrations were higher in the Control group and the foals from the TMS+FM+ECP group than the rest of the groups at birth.
• At 24hrs, the foals in the TMS+FM+ALT treatment group had higher 17αOHprogesterone concentrations and the TMS+FM group showed higher concentrations at 48hrs.
• Pregnenolone concentrations were found to be higher in the TMS+FM group than the TMS+FM+ALT+ECP foals at seven days post-partum.
• Foals categorized as high-risk and those who did not survive had lower cortisol at birth but higher progesterone from 0 to 48hrs. Their concentrations of pregnenolone and 17αOHprogesterone were also found to increase after 12hrs.
• The study concluded that the incorporation of ECP in the treatment of experimentally-induced placentitis seemed to improve the endocrine response and the viability of the foal. Moreover, abnormal cortisol and progestogen profiles were observed in high-risk and non-surviving foals and those treated with ALT or TMS+FM.