Effects of bromocriptine and perphenazine on prolactin and progesterone concentrations in pregnant pony mares during late gestation.

This research investigates the impact of bromocriptine and perphenazine on hormone levels in pregnant pony mares and their effects on gestation and childbirth outcomes.

Introduction

• The study focuses on tracking the impacts of administering bromocriptine and perphenazine to pregnant pony mares during the last phase of their gestation period.
• The researchers allocated the mares into three groups; each group was treated differently to determine the role of these two substances in mare pregnancy.

Methodology

• The mares in Group A were treated with bromocriptine, administrated through injections twice a day starting from Day 295 of gestation until parturition.
• The mares in Group B were orally given perphenazine from Day 305 of gestation until the end of pregnancy.
• Group C served as the control group, receiving saline injections for comparison purposes.

Key Results

• Results evidenced that the mean plasma prolactin and progesterone concentrations were higher (P less than 0.05) in Group C than in Groups A and B from 295 to 309 days of gestation.
• Starting from Day 305, Groups B and C showed higher (P less than 0.05) prolactin and progesterone levels compared to Group A.
• The hormone levels in Group A remained constant, while they rose for Group B and Group C mares.
• Approaching parturition, mares in Group A had lower levels of progesterone and prolactin compared to mares in Groups B and C.

Outcome Implications

• The study showed that all Group A mares were agalactic (failed to produce milk) at childbirth, while all mares in Groups B and C had normal milk secretion.
• Additionally, gestation was longer in Group A than in Group C mares.
• Alarming complications in Group A included mares retaining the placenta for longer periods (more than 3 hours), experiencing dystocia (difficult birth), and having thickened, haemorrhagic placentae.

Conclusion

• The research suggests that the administration of bromocriptine and perphenazine influences prolactin and progesterone levels during late gestation, potentially leading to negative outcomes, particularly with bromocriptine.