Management of Parturition and peri-parturient disorders Flashcards
What is the normal gestation period ?
58-72 days after mating (or 63 days +/1 after ovulation)
What is Parturition (eutocia) initiated by?
Foetal signs -> stress from less nutritional supply from placenta to foetus stimulates foetal HPA axis and release of cortisol
Maturation of the foetus
Describe what are the normal parturition steps
- Parturition in the bitch typically lasts 4-18 hours.
- Stage 1: preparatory stage (uterus and cervix)
- Stage 2 + 3: expulsive stages
- Stage 2 is active labour
- Stage 3 is passage of foetal membranes (often at same time as stage 2)
List predictors of Labour
- Drop in progesterone
- Drop in temperature 1-1.5°C
- Mammary development & lactation
- Vulvular enlargement
- Mucoid vaginal discharge
- Reduced appetite
- Nervousness
How do we define Stage 1 labour
Beginning is defined at the start of uterine contractions after removal of the progesterone bloclk -> supports the opening of the cervix
What correlates to placental separation and cervical dilation ?
Change in ratio of oestrogen to progesterone
How long after progesterone falls does stage 1 start?
24-36h later
why do we see a drop in temp ?
because progesterone is thermogenic -> drop of 1°C is noted in most bitches 1é-2h before parturition -> returns to normal at time of parturition
Role of Relaxin in Stage 1?
Pelvic soft tissues and vagina o relax to facilitate foetal passage
Describe Ferguson’s reflex
- Neuroendocrine Ferguson’s reflex is active → sensory neurons in the cervix and the vagina detect pressure
→ hypothalamus → release of oxytocin → uterine contractions → sensory neurons (+ve feedback loop)
Are there abd contractions in stage 1?
NO
Detail role of prolactin in stage 1?
INC in prolactin 12-24 hrs before onset of parturition -> contributes to bhvr changes
Colostrum production 1wk-> 24h before parturition
What bhvr signs may we see in stage 1?
Restlessness - pantingn tearing up bedding, digging, shivering, V+
How long does stage 1 last?
6-12 hrs but can be up to 36hrs
Detail the main features of stage 2 labor
- Allantchorionic membrane ruptues and clear discharge
- Visible abdominal straining, strong uterine/ and contractions
- Rectal temp back to normal
How long does stage 2 labour last?
normally -12 hrs, should not continue > 24hs
Timings of delivery?
- First foetus usually delivered within 4 hrs
- interval between births normally 30-60 mins -> 120 mins
What happens in stage 3 ?
Passing of the placenta - with or within 15 mins of each foetus -> retaining it rare in dogs
How long is post partum discharge present for - what is it called & what colour is it?
Lochia -> up to 3 weeks - normally green (uteroverdin)
When is uterine involution complete ?
12-15 weeks
Gestation period in the queen?
63-67 days (63 after mating)
Describe stage 1 parturition in the queen?
Up to one week prior to parturition
- Drop in rectal temp less reliable
- Bhvr changes
- Colostrum 1 week to <24 h prior to parturition
Describe Stage 2 & 3 in queen
- Vaginal discharge less common
- Lochia red reddish/ brown
- Interrupted labour
When to worry (points 1-4)
- Failure of the dam to initiate labour at term → need to know ovulation date! Overdue.
- Failure to enter stage 1 → temperature drop (<37.5C) or PG drop but no progression
over 24-36 hours - Failure to enter stage 2 within 36 hours
- Failure to deliver foetus within 1 hour of active labour or 4-6 hours of intermittent labour
* Greater then 2 –4 hours in between foetuses (remember interrupted labour in the cat)
When to worry (points 5-9)
- Constant unrelenting straining
- Foetal distress → stillbirths, low HR in utero, meconium but no pups
- Maternal distress → depressed, pain, copious vaginal discharge or bleeding, in shock
- Irreversible signs/history of dystocia → foetus stuck in birth canal, foetal/maternal
mismatch, malposition, pelvic canal abnormality etc - Breed of known anatomical issues…
what is dystocia
inability to expel a foetus through the birth canal without assistance
List some risk factors to dystocia
- Age
- Size
- Breed -> highest in FBD, Boston terrier, pug, chihuahua
Purebred 3x more likely than crossbreed
Uterine inertia can be: …
Primary complete, Primary partial, Secondary
Define Primary Uterine inertia ?
Failure to establish a functional, progressive level of myometrial contractility -> failure of expulsion
Define Secondary Uterine inertia
Cessation of parturition after it has been initiated -> failure to deliver the remaining fetuses (metabolic, anatomical and genetic causes)