How many cattle need assistance with parturition? horses?
3-25%, especially heifers
1-2% in horses (urgent, dramatic), pigs, sheep
Causes of Dystocia
1. Foetal-pelvic disproportion (size issue)
2. Malpresentation- usually front feed up, head first (orientation issue)
3. Ineffective labour (Mom is not pushing hard enough)
* relates to both :
Foetal birth weight & maternal body weight/ conformation
* If Mom is fat, it is a problem
* Frequency- 50-70% of dystocias in beef, 15-30% in dairy cattle, probably less common in other species
* Cause often not known- foeto-pelvic disproportion contributes; foetal maturity/strength/ coordination
* Especially in posterior presentation
*Range from simple to horrible
* Frequency: 20-45%, relatively common in horses
Dorso-iliac isn't a bad thing
* Weak or ineffective contractions
* Primary: hypoCa, debility, obesity
* Secondary: Exhaustion (obstruction, twins, hydrops)
* Frequency: 10-20% in cattle; less common in horses, the most common cause in pigs, dogs, and cats
vulva= scar tissue- doesn't stretch as well as it could the next time around
Uterine torsion= uterus has rolled- 180 degrees- 540 degrees (3x around)
hydrocephalus- fluid filled heads
Schistosoma reflexus- inside out essentially- happened early week 1, can even be alive-- one dozen per year
Prevention of Dystocia
1. Genetics- some factors can be selected for
* foetal BW, double muscling, gestational length, maternal pelvic diameter (is not the same as hip width)
* Some don't respond well to selection: foetal presentation, posture, position; dystocia itself has low heritability
** Beef production traits linked to same traits that lead to dystocia
* Preweaning growth of heifers: has some effect on size at puberty
* Weaning to mating: growth in this period affects pelvis size
* Mating to 1st parturition: restriction of gestational nurition is an imprecise way to affect foetal growth, restriction of late gestational nutrition carries considerable risk to the dam ** or if you gave extra feed, she will give it to her calf, so skinny cow with big calf**
* excessive intervention- some species differences
* Delayed intervention- timely intervention may prevent a minor dystocia from developing into a serious dystocia
* Frequency and expertise of observation
What do you want to know on your way out to a calving?
Decision making around dystocia in calving
Options with dystocia
* manipulation, extraction, foetotomy, caesarean section, euthanasia (mom)
What does manipulation with dystocia mean?
* Hygiene and lubrication (Benzalkonium chloride, Methylcellulose, K-Y Jelly)
* You are working in a very confined space
* Correct positions and postures if possible-- straighten up the head; the legs
* Don't try to correct presentations- turning posterior to anterior is unrewarding
* minimize the diameter of the calf/ foal/ lamb...
* Protect the uterus at times (teeth for example)
* Use retropulsion intelligently- can push back in
* Minimize maternal straining
* Positioning of the patient
* Directed and appropriate traction-- you can pull in any direction-- 3D-- which is why the cow in the raceway is not good
Prior to starting in dystocia...
* Assess the cow- she's down, for example, in a raceway- we can't move her and turn her-- can we get her out of there-- move some rails off the fence, etc.
* Wash up- warm water over the back of her, it's calming
* Assess the calf's... viability (skin pinching- pulls foot away- if doesn't could just be stuck; feel for a pulse- femoral, side of chest; stick fingers in eye sockets, it moves it's head-- if it doesn't maybe jammed and can't; stick fingers in its mouth-- it will start trying to drink), presentation,
Head flexion- fingers, eye hooks, snares
Rotation of calf- directed traction, manual leverage, detorsion rod, pulley system
When do you use forced extraction?
* Correct any malpresentations first; place chains/ ropes properly; orientate the foetus; dilate the cervix (manually)
* When there is no physical obstruction to passage of the foetus
* When foeto-pelvic disproportion has been assessed
* Don't apply traction to the jaw- very common for farmer
* How hard should you pull? Not too hard
* How do you tell if it will fit? Front feet out of the vulva and the head into the canal- it will likely fit-- if I can't get the hocks out of the vulva- probably too big
* equipment? Jacks, pulleys, people
* Where do you do it? Anticipate the standing patient becoming recumbent
How do you help a small animal with dystocia?
* Space is seriously limited (one finger can get in)
* External manipulation may be more effective (can use your hand and push them from behind)
* Any traction needs to be applied very carefully
What is an episiotomy?
* If the vulval isn't stretching enough- you can do a cut
* Allowing vulva to tear in the direction you want it to tear
* Occasionally useful in cattle but rare
What do you do with a hip-lock?
Direction of pull more important than strength of pull
* Calving jack-- chain on legs (apply tension)-- pull in the direction towards the leg
* Reduction of foetal size by dissection
* Indications: dead calf, alternative to correction of difficult flexions
* Total (2 hours) vs. Partial
* Percutaneous vs. Subcutaneous
What is meant by subcutaneous foetotomy?
Not cutting through bone- just soft tissue
What is meant by percutaneous foetotomy?
Cut up the bone too
- flexible... almost unlimited range of cuts
- simple cuts can be quick
- usually leaves sharp edges of bone
- loss of traction points
- technically demanding: specialized equipment
- can be frustrating and physically challenging
Indications for Caesarean Section
* Unable to extract foetus per vaginal
* Live/ viable foetus(es)
* Valuable foetus(es)
* Elective pre-parturient
* Foetal monsters
* Dead, emphysematous foetus(es)
* Uterine torsion
* Standing (cattle): left flank (not right flank- intestine!!)
* Recumbent: flank, paramedian, ventral midline (anaesthetic risk)
When is euthanasia best?
* animal welfare
Why periparturient disease?
Common problems preparturient, parturient, postparturient?
How can you tell this is vaginal and not uterine? No Cotyledons
Why does this happen? When in horses? Predisposed by?
During pregnancy attaches ventrolaterally-- so a more twisting force to rotate it medially is present and can cause uterine torsion
What self corrects? What causes foetal compromise? What can happen?
<90 degrees self corrects
Room for the feet, not the head, what is the condition?
* Oestrogen and relaxin has relaxing effect on cervix as well
What are the two forms of uterine intertia? What are they?
* Primary and seconday inertia
Uterine prolapse-- no more likely to re-occur in this animal more than any other animal
Consequences: mild cases resolve spontaneously, foetal loss and/or infertility, lactation failure
What does it cause in horses?
Metritis- in horses- common cause of sepsis
Metritis- likely to get some necrosis of the uterus
** this is from a cow you can tell by cotyledons
Why does pyometra occur? When is it likely to occur?
Does it respond well to treatment?
- does not respond well to treatment, likely to end up culling
Differences between endometritis, metritis, and pyometra?
Almost always become infertile
What is the process of placental separation? What can happen, especially in dairy cattle?
What are some predisposing factors in Retained Foetal Membranes?
Consequences of RFM in cows and horses?
What is this condition? Why does it occur? In who?
* impaired ovulatory hormonal signalling
- proposed mechanisms include: decreased pituitary sensitivity to oestrogen stimulus; decreased follicular hormonal receptors
* Predisposed by periparturient stresses:
- dystocia, RFM, ketosis
How do you distinguish a follicular cyst from a preovulatory follicle?
How do you distinguish ovarian cysts from cystic corpora lutea?
What are the ddxs to cystic ovarian disease?
What are effects of cystic ovarian disease?
Ovarian cysts can produce excess androgens-- "bearded ladies" back in the day in the circus
When does uterine torsion occur in horses? Cows? Treatment in horses?
Late gestation in horses (from about 8 months), whereas in cows mostly just at the time of parturition
** Horses treated surgically by flank incision- mare is put on exogenous progesterone for a couple of weeks or until 320 day of gestation
Which was does the torsion occur in cows? How can you tell?
* usually once it has been corrected, it doesn't happen again
What is plank in flank?
* 3 people- Determine way of torsion, put her on one side, tie ropes to feet-- pull the cow over its back... someone stands on the plank while the cow is rolling
* No sedation or anything
* Bilateral distension, apple shaped-- different form bloat which is usually just distension on left side. Cow is sick: anorexic, down, weak, decreased rumen motility)
* If only tight uterine wall can be palpated and no fetal part of placentomes, a diagnosis of hydrops allantois is made. If fetal parts can be palpated other reasons of uterine distension should be considered (twins, triplets, Hydrops amnii, etc.)
* Prognosis is poor for cow's life and fertility. Treatment can be either induction or C- section with slow release of fluid (cow should receive fluid replacement therapy).
Normal on right, left is hydrops allantois- do not have clear area between cotyledons-- called adventitial placentation-- desperate attempt to create more attachment sites
Hydrops amnii- usually means the foetus is malformed-- normally the foetus swallows the fluid, but if it can't swallow, there is a build up of fluid.
** not as massive as hydrops allantois
* Usually fetus and placentomes can be palpated
* cow is usually clinically otherwise unaffected
* prognosis for the cow is much better
* pregnancy usually goes to term and frequently a small, deformed fetus is delivered-- may induce
* Postpartum metritis is uncommon (unlike hydrops allantois)
* No treatment required
Usually older mares, not athletic breeds, 16 yo draft mare for example
* LIkely not an actual rupture of the pre-pubic tendon but rather a tear in the abdominal muscle
* first sign is ventral oedema-- followed by dropped abdomen
** Tx: abdominal support and reduced activity. Parturition or induced or assisted or an elective C- section has been the traditional treatment. Waiting and letting the mare foal may result in a better prognosis for both foal and mare vs. C section.
What is often the cause of haemorrhage with pregnancy?
Post- partum * Bleeding into broad ligament after uterine artery rupture (older mares often)
* Clinical signs: colicky post foaling, high heart rate, prolonged CRF
* Treatment: keep quiet, maybe fluid replacement
* Mare should not be stressed/ transported
* Vulvar and vestibular lacterations are quite common and usually do not require repair if they only involve the mucosa. If the submucosa is involved, immediate suturing is indicated to prevent contamination.
** usually just a wait and see, if you're lucky she will make it
* take the foal out, due to colicky symptoms if they occur
What is a common perforation with parturition?
Recto-vaginal perforation: foot comes through the anus; leads to recto-vaginal fistula.
Third degree perineal laceration; tear of vulva, perineal body and anal sphincter; creates cloaca
** suture if you're there straight away; but if you are called later will have to wait to do reconstruction-- can rebreed next season
Necrotic vaginitis following trauma during dystocia
Uterine prolapse- rare in mares. Poor prognosis for future fertility and guarded for survival. Replacement may be possible if hind- end of mare can be elevated and the organ is not necrotic.
* most common in dairy cows and ewes
* acute condition usually immediately after or within a few hours of parturition. Often associated with hypocalcaemia and may also follow use of great force in fetal extraction. Not hereditary. Can involve other organs such as the bladder or intestines. In some cases, the uterine artery may rupture--> death
* Treatment: epidural anesthesia is helpful to prevent straining-- elevate the hind quarters-- it may help to empty the bladder-- generally the placenta is removed only if loose. Takes patience to get it back in. can put antibiotics on uterus before you put it back in. Complete replacement is essential. Oxytocin should be given after replacement. If given before, will make replacement more difficult. can suture vulva, many think unnecessary if right location.
** use a wine bottle to help get horns in the right place.
In a cow, when is it considered a RFM?
more than 12 hours (normally delivered within 2 to 6 hours)
* often wait and see approach if cow is not systemically ill. Intrauterine or systemic antibiotics can be given.
> 24 hours even in cattle should be concerned, increased risk of metritis, start taking temperature-- antibiotics.
In a horse, when is it considered RFM?
* Life threatening emergency: e.g. laminitis, septicaemia, toxic shock and death
* Normally released within 1 hour; retained if not released within 4-6 hours. Antibiotics required after 6 to 8 hours.
* Attend if FM not passed 4 hours post foaling
* Can try 10 IU oxytocin q 45 minutes
* If no progress within 2 hours, start treatment with antibiotics (AB treatment should start within 6 hours of parturition or mare is at risk)
* Septic/ toxic metritis happens very fast
** Don't just pull it out- risk of trauma, haemorrhage, severe uterine damage
*Can try to get a hold of the RFM and wrap them into a cord and then apply very light traction, while feeling rectally, where they are attached. That area can be massaged rectally and often they will be released
** flush with saline or Ringer's after everything is out until the recovered fluid is clear- oxytocin is continued for another 24 to 48 hours in order to aid uterine involution
Medication for RFM in horses
What is puerperium?
The time between birth until reproductive function is restored (lactation, uterine involution, return of ovarian cyclicity)
What is uterine involution?
Changes in the uterus that result in returning the organ to normal size after parturition
4 overlapping processes:
1. Myometrial contractions and expulsion of Iochia
2. Necrosis and sloughing of tissues
3. Repair and growth of surface epithelium
4. Removal of bacterial contamination
Deciduate vs. non-deciduate placentation
How does a cow get rid of its placenta?
1. Myometrial contractions and expulsion of Iochia
2. Necrosis and sloughing of tissues
* A combination of blood loss, placental maturation and strong contractions needed to separate the placentomes
* Contractions subside in a couple of days: myometrial cell size drops 700 micrometers to 200 micrometers in days
* Necrosis and sloughing of caruncle takes days
What happens after the extra-foetal membranes are lost? Time periods too.
3. Repair and growth of surface epithelium
4. Removal of bacterial contamination
* Repair of inter-caruncular regions usually by day 8
* Caruncular regions vary- often by day 20 but can be delayed
* bacterial contamination common
Bovine involution- what is the primary stimulus for change? What hormones? What else assists?
* removal of foetus
* oxytocin and prostaglandin
* Uterine contractions continue for several days although reduce in regularity, frequency, and amplitude (occur at 3-4 minute intervals)
How long does it take for the uterus to become sterile after parturition?
Sometimes 6-8 weeks
80-100% have bacteria in there for the first few weeks, gradually declines
What can go wrong with bovine involution?
* Prolapse uterus
What are the three steps involved in expulsion of the membranes? Risk factors?
1. Maturation of the placenta
2. Exanguination of the foetal side of the placenta after the blood supply is cut off (which causes physical shrinkage)
3. Uterine contractions (causing distortion)
- slow calvings, dystocia (slows exanguination)
- low energy (causes slow calvings)
- low calcium (smooth muscle contraction)
- infection (slows maturation)
What is Lochia?
Uterine fluid, placental fragments, caruncles
* discharged for 2 weeks postpartum. Normally red-brown, odourless. If it becomes stinking, uterus infected.
* Should cease by day 30 at the latest.
* Severity of infection depends on immune system, BCS of cow, nutrition, stress, bacterial species, etc.
* Most bacteria are eliminated by the uterine defences
What is endometritis? Why is it a big deal?
* infection of endometrial lining
* lowered fertility if it persists
* 15% can develop it chronically
* persists 3 weeks usually
CLinical signs: purulent discharge in uterus, occasionally at vulva, failure to conceive, massive infiltration of neutrophils into uterus, rarely act sick
Diagnosis of Endometritis
Typical occurrence of endometritis
Risk factors of endometritis
Control of endometritis
Pathogenesis of Pyometra
No PG so can't be expelled- gradually gets bigger and bigger
Pyometra treatment and prognosis
Why is delayed involution a problem?
* Can increase the time to pregnancy by months
* Very important economically
* vets spend a lot of time managing this
Why is RFM less a problem in sheep?
* different placentomes
Summary of involution in different species (general)