Parturition, Dystocia, Post-Partum and Reproductive Surgery Flashcards
Holly is 325 day into her pregnancy and over the last 2 weeks has developed a significant ventral abdominal bulge.
This morning the swelling was dramatically worse, she is clearly in pain, has HR of 62 and a wide base stance. There is significant oedema on palpation
What is the likely diagnosis?
What are the challenges for Holly?
How might you assist?
Ddx - abdominal wall rupture (pre-pubic tendon)
Challenges - Expulsion of the foetus will be difficult because abominal musculature is weakened
Assist - Might need to induce parturition to help deliver the foal
What characterises a ruptured pre-pubic tendon or abdominal wall rupture? How can it be managed?
- Occurs mainly in heavy horses
- Mares often old
- Characterised by massive ventral swelling and oedema, abdominal pain and often recumbency
- Mare develops a ‘saw horse’ stance with legs extended
Management
* Use of belly band in late pregnancy?
* Prognosis is poor because mare cannot generate expulsive abdominal effort
* Parturition normally need to be induced
* Live foals may be produced by assisted delivery after parturition-induction
* Traction is usually required
What drugs would induce parturition in the mare?
Low dose oxytocin regimes given in repeated IV boluses until parturition
* 10 IU given IV every 20 minutes until parturition commences
* Most mares respond within 15 – 90 minutes (i.e. 1 to 3 doses)
Higher dose oxytocin regimes given as single dose intramuscularly
* 40 IU given IM
* Appears to produce a longer duration parturition than the lower IV bolus dose regimes
Slow intravenous infusion of oxytocin
* 60 - 120 IU diluted in 1 litre of saline and infused IV at 1 unit/minute
* Appears to produce a longer duration parturition that the lower IV bolus dose regimes
What are the indications and possible complications of inducing parturition in the mare?
Indications
* Mares with dystocia or premature placental separation in previous deliveries
* Mares with abnormalities such as rupture of the prepubic tendon
* Mares that are very uncomfortable with marked ventral oedema and are running milk and have an open cervix (some mares with ascending placentitis)
Complications
* Most mares will require assistance delivering foals
* Induced parturition is also associated with:
* Dystocia due to inability of the foal to rotate during expulsion
* Premature placental separation
* Fetal hypoxia or fetal death
* Dysmature / immature foals which have difficulties adapting to extra-uterine life and may die
What criteria need to be met before we induce parturition in the mare?
- Adequate gestational length – at least 330 days although most veterinary surgeons would not consider induction until well past this time
- Adequate mammary development and milk/colostrum production
- Suitable softening of the cervix:
- Although there is some debate about how important a completely relaxed cervix is for successful induction
How can parturition be predicted?
- Date of conception
- Estimation of fetal age using ultrasound
- e.g. diameter of the eye
- Relaxation of pelvic ligaments
- Waxing up of the teats
- Change in mammary secretion
- Sodium:potassium ratio 4 days before foaling
- Calcium increases to more than 10 mmol/l 1-2 days before foaling
Which are the most common causes of dystocia in the mare?
Faulty disposition
Weak abdominal straining
Feto-maternal disproportion is UNCOMMON
What are the common abnormalities in position in the foal at parturition?
- Elbow lock
- Foot-nape position
- Carpal flexion
- Neck flexion
- Shoulder flexion
- Dog-sitting position
- Hock flexion
- True breech
- RV fistula can be fixed by creating 3rd degree perineal laceration does not require retro-pulsion
What are the 3 classes of perineal injuries following parturition?
First degree
- skin and mucosa (usual of dorsal comissure)
Second degree
- deeper laceration involving muscle of perineal body
Third degree
- torn vagina and rectal wall (creating a cloaca)
Recto-vaginal fistula
- penetration from the vaginal cavity into the rectum but not continuous distally
How should you manage contusions and lacerations following parturition in the mare?
- Usually best to delay repair as heal well without treatment
- Except third degree laceration
- NSAIDs + topical treatments (lavage etc)
- Don’t forget tetanus status
What different structures can prolapse following parturition in the mare?
Prolapse of the uterus
* Uncommon. Commonly at assisted parturition with traction or attempts to remove placenta, or XS oxytocin administration
* Can be fatal haemorrhage
* Replacement is easier than cow
Eversion of the bladder
* Uncommon. Bladder mucosal surface evident
* Can be replaced with epidural
Prolapse of rectum
* Rare. Usually fatal
How is the placenta normally delivered following parturition in the mare?
- Allanto-chorion ruptures
- Foal born within amnion
- Umbilical cord and amnion hanging from vulva
- Umbilicus attached at base of horn where implantation occurred
- Weight provides traction (therefore do not cut rather tie them up so mare does not kick at them but maintains weight)
- Detachment from apex so placenta everts as it detaches
- Normal placental passed within 3 hours of foaling
How soon following parturition should the membranes have been expulsed? What are the consequences of retained foetal membranes? What should you do if they haven’t been expulsed?
- Retention for more than 3 hours is considered abnormal
- Severe sequelae mainly in heavy horses (metritis-> laminitis)
Treatment
* Bandage tail
* Clean vulva
* Separate allanto-chorion from uterus at vulva
* Twist allanto-chorion so force evenly applied
* Insert hand between uterus and allanto-chorion
* If haemorrhage or not easily separating – STOP
* Either attempt oxytocin treatment or preventative treatments and revisit in 8 hours
* fill the foetal membranes with saline and then tie off anf follow single dose oxytocin regime
* Systemic antibiotics
* Uterine antibiotics – site?
* NSAIDs
* Calcium
* Others
Twiggy foaled 4 days ago. The placenta was passed but was not examined.
Today she is depressed, pyrexic, and has a HR of 55.
What condition could this be?
What is the under-pinning aetiology?
This mare has metritis
Risk is laminitis - pedal bone rotation
What can cause post partum metritis? How should it be treated?
Serious condition in mares with retained placenta or following dystocia or assisted parturition
Treatment
* Attempt to cause placental separation should be made
* Removal of uterine fluid using scooping and/or lavage with 1-2 litres saline and immediate drainage by siphonage
* Broad spectrum antibiotic systemically
* Local infusion of antibiotic into the uterus
* NSAIDs
* Vasodilators etc
* Treatment is repeated daily until the pus and placental debris have disappeared
Philomena foaled at grass 7 days ago. It has been very cold and the ground is frozen and she has been quite hungry. The foal is sucking well.
This morning she did not seem able to nibble at the grass, and what she did pull up fell out of her mouth. This afternoon she has developed some kind of fasiculations
What metabolic condition might be going on here?
What features point to this as a diagnosis?
What diagnostic tests do you need to confirm a diagnosis?
Early phase of hypocalcaemia
Muscle fasciculations, jerky, looking alert
Biochem
When does hypocalcaemia occur post partum? What clinical signs are associated?
- Seen immediately pre or post partum
- Often associated with restricted food intake
- Not associated with recumbency until severe
- Mild cases appear to be hyperaesthesia and dry faeces
- This is followed by inability to prehend food (which worsens the condition)
- Subsequently there is diaphragmatic asynchrony (‘thumps’)
- Treatment is slow infusion of calcium borogluconate to effect whilst continuously monitoring cardiac activity
What surgical procedures are available to correct perineal conformation?
- Caslick vulvoplasty
- Episioplasty
- Perineal body transection (Pouret’s Operation)
- (Urethral lengthening)
What is the aim of the Caslick’s vulvoplasty? When is the procedure indicated? What are the steps of the procedure? When is it most commonly done? What complications can occur?
Aims to close the dorsal commissure of the vulva and so improve the vulval seal
Indications:
* Correction of mild conformational abnormalities which cause pneumovagina
* Sunken anus
* Sloping of the vulva
Creates a small vulval orifice
Technique
* Restrain mare
* Clean vulva
* Local infiltration
* Remove 4 mm wide strip of vulvar mucosa at m-c junction
* From the dorsal commissure to level of bony pelvis
* Do not remove skin as that will cause fibrosis
* Close with interrupted or continuous sutures
* Remove sutures (faeces stick to sutures)
Done after confirmed pregnant at 21 days
- Remove “Breeder’s Stitch” and replace with Caslick Repair
Complications
- Faecal accumulation on sutures – can increase bacterial loading
- Wound breakdown
What do you need to do when a mare with a Caslick is foaling?
Episiotomy required before foaling but if the procedure has been done well this is a simple fibrous band within the mucosa that can be cut but would tear safely if this is not done
What is the aim of an episioplasty? What is it indicated? How is it undertaken? What complications can occur?
Aims to produce some reduction in diameter of the vestibule
Indications:
* Correction of moderate conformational abnormalities which lead to pneumovagina
* Elevated vulva in relation to pelvic floor
Restores some degree of perineal function
Technique
* Mare standing - epidural anaesthesia
* Incise into mucocutaneous junction from the dorsal commissure to the level of the pelvic floor (just like episiotomy in bitch)
* Retract labia with stay sutures
* Remove a triangular piece of dorsal vestibule wall (apex of triangle caudally)
* Repair mucosa and close labia as in Caslick’s operation
* Do not breed for 4 weeks
Complications
Vestibule reduced in size
* Care during covering
* May need episiotomy at foaling
Complications:
- Wound breakdown
What is the aim of a perineal body transection (Pouret’s)? When is it indicated? How is it undertaken? What complications can occur?
Aims to increase the distance between the anus and the vulva
Indications:
- Correction of severe conformational abnormalities which lead to pneumovagina
Restores anatomy and function
Technique
* Standing mare - epidural anaesthesia
* Horizontal incision between anus and dorsal vulva
* Blunt dissect between muscles of perineum
* Dissect cranially for 10 to 20 cm and in so doing allow the vulva to hang more ventrally
* Distance determined by when vulva is vertically positioned
* Either:
* Close wound in vertical manner, or,
* Pack wound with swabs; leave to heal by 2nd intention
* Do not breed for 4 - 6 weeks
Complications
* Penetration of peritoneum at surgery
* Wound breakdown
How would you repair a 3rd degree perineal laceration?
Treatment
* TAT
* Antimicrobials
* Local irrigation
* Vaseline
* Leave 5-6 weeks for second intention healing
* Ensure viable edges for suturing
Advise owner
* No use for that breeding season
* Anus may never function again
* May require more than one attempt at surgical repair
Preparation
* Soft faeces before surgery
* Sedation, epidural, standing
* Evacuate rectum
**Surgery **
* Identify shelf of tissue
* Incise along lateral walls of vagina at this level
* Create 2 flaps of lateral vagina
* Suture flaps together from cranial to caudal in midline suturing only sub-mucosa and lateral wall rectum to re-create dorsal roof
* Do not suture anal sphincter
* Ensure defaecating at day 1 (painful)
* Re-examine at 3 weeks and suture perineum (like Caslick’s)
