Uterine involution Flashcards
What is uterine involution?
- Reduction in uterine size
- Repair of endometrium
- Expulsion of lochia
Describe uterine involution in the cow
- Day 1pp= Cervix closes within 12-12 hours than involutes
- Day 4pp= lochia forming
What is the mechanism for uterine involution?
- Myometrial contractions produce peristaltic waves towards the cervix= these cause discharge of fluid/ tissue debris and act to compress vasculature. Stimulated by oxytocin and PGF2a
- Coordinated atrophy of myometrial cell size.
What stimulates the myometrial contractions during uterine involution?
-Oxytocin and PGF2a
What is lochia?
- Blood tinged discharge containing debris of fetal placenta and endometrium
- Caruncles slough between days 5-10
Discuss the repair of the endometrial tissue
- 2 days PP= septal mass with early necrosis
- Days 5-10 PP= sloughing of the necrotic septal mass
- Days 10-15 PP= Mass has sloughed off and vascular stubs formed
- Day 20 PP= smooth surface of endothelium returned
- Whilst this is occurring the myometrial layer is thinning
How long does uterine repair take in a cow?
Beef=30 days
Dairy=35-45 days
Discuss uterine involution in the mare
- Very raid as is hastened by foal heat
- Small amount of lochia= should stop after 1-2 days
- Endometrium should be normal after 14 days
- Post partum infection with coliforms is very common-> should be eliminated by foal heat.
Discuss uterine involution in the bitch
-Has 2 lochia:
1st= immediately after birth, is green in colour, then 2-3 days PP is red/ watery then mucoid
2nd= 4-6 weeks PP
-Endometrium repair is slow= takes approx. 3 months
Name 2 opportunistic pathogens that can cause whites
-Trueperella pyogenes and fusobacterium
Discuss ovarian rebound in the cow
-Days 5-10PP= Pituitary gland refractoriness to GnRH decreases, FSH wave leads to follicular wave development
-Days 10-20 PP= increased sensitivity to GnRH -> LH secretion as follicles get bigger
Ovulation (silent oestrus)
-Ovarian cyclicity re-initiated with short 1st cycle.
