Puerperium - Sheep and Goat

Also see General Puerperium

The puerperium is similar to the cow (ruminants in general have a similar puerperium. The main difference is that, since they are both seasonal breeders, parturition is followed by a period of anoestrus.

Involution

• Rapid shrinkage and contraction of the uterus.
  • Particularly during 3-10 days postpartum.
• Involution complete by 20-25 days.
• In the ewe, involution is also due to collagen breakdown.

Restoration of the Endometrium

• Hyaline degeneration occurs during the prepartum.
  • Occurs in the connective tissue in the base of and adjacent to the endometrial crypts. It also involves the walls of arteries and veins.
    • Lumen of arteries and veins becomes reduced
    • Foetal villi unaffected
• After dehiscence and separation of the placenta there is further hyaline degeneration of caruncular tissue.
  • Results in constriction of the blood vessels at the base of the maternal crypts.
• Necrosis of the surface layer of the caruncle.
• 4 days postpartum, most superficial layers undergo autolysis and liquifaction.
  • Causes dark red/brown or black colouration of lochial discharge.
  • Quantity of lochia is variable.
    • Initially arises from blood, foetal fluids and placental debris.
    • As the puerperium proceeds, sloughed caruncular tissue contributes to it.
• By 16 days postpartum, necrosis of the whole caruncle has occured.
  • Separation of the brown necrotic plaque, so it lies free in the uterine lumen.
  • Caruncles have clean, glistening surface.
• Re-epithelialisation of caruncles is complete by 28 days postpartum.

Return to Ovarian Cyclicity

• Ewes normally become anoestrus after lambing in temperate climates.
• Sometimes ovarian activity can occur within a few days - 2 weeks postpartum.
• Follicular growth is common, ovulation is unusual
• If ovulation occurs it is usually with a silent oestrus.
• Failure of follicular maturation and ovulation is due to a lack of LH as a result of deficient GnRH synthesis and secretion.
  • Basal LH levels and the frequency of LH secretion is inadequate to stimulate normal ovarian function.

Bacterial Elimination

• Does not commonly occur as it does in the cow and mare.
• Swabs taken in the postpartum period usually reveal a sterile uterine environment!