Parturition, Dystocia, Post-Partum Events and Reproductive Surgery Flashcards
What has occured here?
- This mare is 1 day after foaling
- What is the abnormality present?
- What actions would you take?
- Dramatic swelling of perineal region
- She has a complete connection between the rectum and vagina what has happened in this case is one of the foal’s feet has protruded dorsally through the anus creating a cloacal like defect.
- Need to clean up and debride there is an awful lot of tissue that is going to slough atm so it is not the best time to suture yet. Lots of swollen devitalised tissue clearly lots of infection going on.
- We need to think about general care of horse: analgesia, antibiotics, general nursing care and wound management and suturing much further down the line when the swelling and infection has died down.
Discuss ruptured pre-pubic tendon or abdominal wall rupture?
- 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
- These mares cannot effectively push so dystocia can follow
How can a ruptured pre-pubic tendon or abdominal wall rupture be managed?
- Use of belly band in late pregnancy?
- Prognosis is poor because mare cannot generate expulsive abdominal effort
- Live foals may be produced by assisted delivery after parturition-induction
- Traction is usually required
What is normal pregnancy length in horse?
Normal pregnancy
–Duration between 310 and 370 days
–Gary does not normally worry about a long pregnancy can usually be due to some placental disease which means foal has not got all the nutrition it needs in the usual time period
–Occasionally it may be 390 days and owners get concerned
•However there is not normally oversize and dystocia as a result
Parturition can be predicted by?
–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
Discuss indications for induction of parturition?
Indications (make sure someone is around constantly as soon as parturition is induced)
- 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
Discuss complications of induced parturition?
- 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 is the criteria for induction of parturition?
- 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
–Some veterinary surgeons routinely treat with 5 – 10 mg oestradiol per mare 24 hours before attempting parturition induction in the belief that this aids softening of the cervix
What is a method for induction of parturition?
Low dose oxytocin regimes given in repeated IV boluses until parturition
–10 IU is given IV every 20 minutes until parturition commences
–Most mares respond within 15 – 90 minutes (i.e. 1 to 3 doses)
–Based on literature easiest and safest routine
What is a method for induction of parturition?
Higher dose oxytocin regimes given as single dose either intramuscularly or intravenously
–40 IU is given IM
–Or, 60 - 120 IU diluted in 1 litre of saline and infused IV at 1 unit/minute
–These regimes appear to produce a longer parturition that the lower dose regimes
What is a method for induction of parturition?
Twice the luteolytic dose of prostaglandin (Dinoprost)
–More effective the closer the mare is to term
Most mares undergo parturition within 4 hours
Interval to parturition may however be up to 56 hours
–Parturition may take longer than normal mares or those induced with oxytocin
Discuss methods of induction of parturition?
NB: Oxytocin regimes are probably the methods of choice but currently there is little evidence to demonstrate differences in neonatal survival with any regime
Discuss foal dystocia?
- The foal should rotate and extend
- Early recognition important this is an emergency
- Strict cleaning of arms and equipment
- Plenty of lubrication
- Suitable equipment for anchoring and later traction
- Quickly establish if the foal is alive
- Need rapid identification of presentation, position and posture
- Is this fixable or does it need referral
- What is prognosis for future fertility
Remember the diameter of the foal vs diameter of the pelvis and the orientation of the birth canal for manipulation and traction. But remember how common is Feto-maternal disproportion?
- Feto-maternal disproportion is uncommon (size of the foal is governed by size of its placenta and the placenta size is governed by size of the uterus)
- Poor rotation/presentation is the main cause of dystocia in the horse
- Common abnormalities
–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 retropulsion
Why is it important to examine the placenta after parturition?
- Important to check
- Common is that the mare retains parts of the placenta which predisposes to the metritis leading to toxaemia leading to laminitis.
Discuss Post Partum Conditions in
the Mare?
Contusions and lacerations
- Common: 3 classifications of severity
- Usually best to delay repair as heal well without treatmen
- Except third degree laceration
- NSAIDs + topical treatments (lavage etc)
- Don’t forget tetanus status
Discuss contusions of the birth canal?
Cervical, vaginal, vestibular and vulval trauma
- Bruising commonly occurs during parturition . Especially in animal is fat or foetus is large
- Vulvar damage is apparent, deeper damage is only observed if animal is examined per vaginum
- Long tears may occur v’ithin vagina and vestibule without long term sigrficance (they cause considerable pain in the short term)
- Often defects can be easily repaired with procedures similar to Caslick’s operation
Discuss perineal injuries?
Most commonly seen in cow and mare, often at first parturition, and most commonly when there has been forced traction
Classified as
- First degree . Skin and mucosa (usually of dorsal commissure)
- 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
Discuss common perineal injuries in the mare?
Commonly the result of foals foot perforating the roof of the vagina or lips of the vulva
- 3 degree laceration therefore appears more common
- Recto-vaginal fistule also appears more common
- 1 and 2 degree are not uncommon and can be treated conservatively or with immediate or delayed suturing depending upon the degree of devitalised tissue
List post partum coniditions?
- Trauma/laceration
- Haemorrhage
- Prolapse of something
- Recumbency/nerve damage
- Placental retention
- Poor/delayed uterine involution/metritis
Look at some contusions and lacerations?
Look at these lacerations and contusions?
Discuss Haemorrhage as Post Partum Conditions in
the Mare?
Haemorrhage
•Of vessels within broad ligament
–Usually build of pressure produces haemostasis
–Haematoma may be palpated in the broad ligament
–Occasionally catastrophic but usually associated with uterine prolapse
Discuss the prolapse in Post Partum Conditions in
the Mare?
Prolapse
•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 aslong as you can stop the mare from straining
•Eversion of the bladder
–Uncommon. Bladder mucosal surface evident
–Can be replaced with epidural
•Prolapse of rectum
–Usually fatal
Discuss prolapse of the rectum?
Slight eversion of a small portion of the rectum may occur during straining efforts.
Severe prolapse only occurs in the mare
Here it can be fatal even if rapidly replaced because tearing of the mesentry of the colon results in infarction of the distal colon resulting in death after a few days
When present and not devitalised it can be replaced under epidural anaesthesia, although if devitalised a sub-mucosal resection will be required
Discuss protrusion or prolapse of the bladder?
In some cases (ewe or cow) the bladder prolapses through a tear in the vagina
In other cases (mare) the bladder everts through the large urethra
Following epidural anaesthesia the bladder should be cleaned and repaired before attempts to re-position (and repair the vagina if the prolapse is through a vaginal tear
Discuss normal events in the passing the fetal membranes?
Normal events
- 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
Discuss third stage parturition?
Uterine contractions cause:
Opening of endometrial crypts
Exsanguination of the placenta (by the squeezing effect of uterine contractions)
Separation of the foetal membrane
As a result, for diffuse placentae such as the mare the apex of the allantochorionic sac becomes inverted and the sac is ‘rolled’ down the uterine horns School of Veterinary Medicine and Science
What is considered abnormal for fetal membrane passing?
Cautiously: retention for more than 3 hours is considered abnormal
What are the consequences of retained fetal membranes?
Severe sequelae mainly in heavy horses (metritis-> laminitis)
What is the treatment for retained placenta?
•Treatment
–Bandage tail
–Clean vulva
–Separate allanto-chorion from uterus at vulva
–Gather the membranes and twist
•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
- Systemic antibiotics
- Uterine antibiotics – site?
- NSAIDs
- Calcium
- Others
Discuss oxytocin treatment for retained placenta?
Treatment
–Oxytocin administration (some clinicians prefer this as an initial approach)
- Ideally intravenous drip and 10 to 50 IU is given in 1 litre of saline over 1 hour
- Single dose of 20 - 40 IU is given IM (may cause XS straining and some increased risk of uterine prolapse) often second or third dose is required
- Single dose 10 IU given IV by some clinicians with claimed no adverse effects
–Unless placenta comes away very easily need daily antibiotic and anti-inflammatory treatment and daily uterine lavage
–Or, fill the fetal membranes with saline (usually water see pic) and then tie off and follow the single dose oxytocin regime to give the effect of a mass for the mare to contract against
–Remember we also discussed prevention and treatment for laminitis which is the important sequelae
Discuss Post-Partum Metritis?
- Serious condition in mares with retained placenta or following dystocia or assisted parturition
- Should be treated as urgent to prevent pedal bone rotation
What is the treatment for post partum metritis?
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
Discuss Hypocalcaemia?
- Not associated with recumbency until severe
- But seen occasionally immediately pre or post partum
- 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
Discuss Surgery to correct perineal conformation?
–Caslick vulvoplasty
–Episioplasty
–Perineal body transection (Pouret’s Operation)
–(Urethral lengthening)
Discuss Caslick’s Vulvoplasty?
- 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
What is the technique for caslick’s vulvoplasty?
•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)
What is a breeders stitch?
Consider temporary “breeders stitch” which does not involve the mucosal membrane
What is Caslick’s Vulvoplasty?
Complications
–Faecal accumulation on sutures
–Wound breakdown
Discuss Episioplasty?
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
What is the technique for episioplasty?
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
Discuss considerations/complications of Episioplasty?
Vestibule reduced in size
–Care during covering
–May need episiotomy at foaling
Complications:
–Wound breakdown
Discuss Perineal Body Transection (Pouret’s Operation)?
- 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
What is the technique for Perineal Body Transection (Pouret’s Operation)?
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
Discuss complications of Perineal Body Transection (Pouret’s Operation)?
Complications
–Penetration of peritoneum at surgery
–Wound breakdown
DiscussRepair of 3rd Degree Perineal Laceration?
- Horrific appearance of vaginal and rectal wall
- Haemorrhage and oedema and tissue sloughing
- Faecal contamination of the vagina
- Necrosis and sloughing for 7 days
- 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
Discuss preparation of Repair of 3rd Degree Perineal Laceration?
Preparation
–Soft faeces before surgery
–Sedation, epidural, standing
–Evacuate rectum
How is surgery for Repair of 3rd Degree Perineal Laceration done?
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)
Discuss repair of Repair of Recto-Vaginal Fistula?
- Create 3rd degree laceration surgically
- Repair as for 3rd degree laceration (convert it to 3rd degree in order to repair)
Discuss Clitoral Sinusectomy?
- To remove the sinus areas to ensure that CEMO cannot be harboured prior to export
- Technique
–Infiltrate lateral lips of the vulva
–Retract with stay sutures
–Infiltrate clitoris if vulval block inadequate
–Use rat-toothed forceps and scissors and ablate dorsal half of clitoris
–Place in transport medium for bacteriological investigation
–Haemorrhage is minimal but can be contained by applying pressure from swab soaked in adrenaline
When is an ovarioectomy considered in the mare?
Granulosa Cell Tumour
- Treatment is unilateral ovariectomy
- Procedure for ovariectory in mares:
- Either in standing mare with flank incision or recumbent mare with paramedian incision
- Its helpful to palpate per rectum to see where the ovary can be moved to as this facilitates planning of incision .
- Routine approach, exteriorise ovary and ligate pedicle or use staples.
- Some surgeons still use ecraseur
- This mare is 6 hours post foaling.
- Are you worried?
- What are you going to do?
- Has retained placenta.
- It should pass within 3 it is now outside normal window. So need to see asap.
- May come away manually so twist it and manually remove
- If it doesn’t not come away manually give oxytocin (give in infusion 10IU in litre and infuse slowly)
- Fill with saline first then give oxytocin so there is a volume effect created
- Need to give supportive treatment: footpads, sole supports, NSAIDs, intrauterine antibiotics (around the placenta), re-examine mare regularly
