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!