Puerperium - Mare

Also see General Puerperium

The puerperium is shorter than in the cow, with rapid involution and good conception rates at the first postpartum oestrus.

Involution

• Lochial discharge is slight in most mares and usually ceases 24-48 hours after foaling.
• Uterine horns shrink rapidly, reaching pre-gravid size by day 32 postpartum.
• Cervix remains slightly dilated until after the first oestrus.
• Involution delayed by retained foetal membranes.

Restoration of the Endometrium

• Endometrium capable of sustaining a pregnancy (fully restored) by 13-25 days postpartum.
• Small amounts of villous debris attached to maternal crypts are removed by autolysis.
• Maternal cryps disappear due to:
  • Lysis
  • Shrinkage of endometrial epithelial cells
  • Condensation of contents of epithelial cells
  • Collapse of the crypt lumen

Return to Ovarian Cyclicity

• Rapid
• Foal heat occurs 5-12 days postpartum.
• Follicular activity after day 2 postpartum.

Bacterial Elimination

• Bacterial contamination of the uterus from the environment is frequent, occuring by the same method as in the cow.
• Organisms usually eliminated during foal heat or disappear at second postpartum oestrus.