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!