Mid-gestation pregnancy is not disrupted by a 5-day gastrointestinal mucosal cytoprotectant oral regimen of misoprostol.
Authors: Jacobson C C, Sertich P L, Mc Donnell S M
Journal: Equine veterinary journal
Summary
# Editorial Summary Misoprostol is commonly prescribed as a gastrointestinal cytoprotectant during colic treatment in horses, but its safety in pregnant mares has been unclear given its known abortifacient properties at higher doses. Jacobson and colleagues administered 5 µg/kg misoprostol orally twice daily for five days to eleven mid-gestation mares (ranging from light horses to ponies) whilst monitoring cervical tone, conceptus viability via transrectal ultrasonography, and hormonal profiles (progesterone and oestrone sulphate) throughout treatment and for five days post-treatment; behavioural observations via video sampling provided additional welfare data. No adverse effects on pregnancy were detected: cervical tone remained appropriate, uterine and fetal ultrasonographic characteristics were unremarkable, hormone concentrations remained stable, and treated mares showed no signs of systemic illness or behavioural distress compared to controls. Whilst these findings offer reassurance for veterinarians needing to treat colic in mid-gestation mares, the authors acknowledge important limitations—the study did not examine earlier pregnancy stages, extended treatment durations, or potential neonatal effects—meaning practitioners should remain cautious and consider this a five-day safety window rather than blanket approval across all gestational ages.
Read the full abstract on PubMed
Practical Takeaways
- •Misoprostol can be safely used as a gastrointestinal cytoprotectant for colic treatment in mid-gestation pregnant mares without disrupting pregnancy
- •A 5-day course at standard dosing (5 µg/kg twice daily) does not require pregnancy termination or pose measurable risk to the conceptus during mid-gestation
- •Further safety data are needed for earlier/later gestation stages and longer treatment durations before extrapolating beyond mid-gestation use
Key Findings
- •Misoprostol at 5 µg/kg twice daily for 5 days did not disrupt mid-gestation pregnancy in 11 mares
- •Cervical tone, uterine and fetal ultrasonographic characteristics, and progesterone/oestrone sulphate concentrations remained similar between misoprostol and control groups
- •No adverse effects on general health, behaviour, or comfort were observed during misoprostol treatment in pregnant mares
- •Results provide assurance of safety for 5-day oral misoprostol regimen in mid-gestation pregnant mares