Week 5 Flashcards
How many cattle need assistance with parturition? horses?
3-25%, especially heifers
1-2% in horses (urgent, dramatic), pigs, sheep
Causes of Dystocia
- Foetal-pelvic disproportion (size issue)
- Malpresentation- usually front feed up, head first (orientation issue)
- Ineffective labour (Mom is not pushing hard enough)
- Other
Foeto-pelvic disproportion
* 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
Malpresentation
* 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
Presentation?
Anterior= frontwards
Posterior= backwards
Transverse= sideways
Position?
Dorso-iliac isn’t a bad thing
Posture?
Ineffective labour
* 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
Insufficient Dilation
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
- 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
- Nutrition:
* 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**
- Management:
* 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
Foetotomy
* 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
Advantages:
- flexible… almost unlimited range of cuts
- simple cuts can be quick
Disadvantages:
- 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
Where?
* Standing (cattle): left flank (not right flank- intestine!!)
* Recumbent: flank, paramedian, ventral midline (anaesthetic risk)
When is euthanasia best?
* animal welfare
* Cost
Why periparturient disease?
Common problems preparturient, parturient, postparturient?
Uterine displacement
Uterine displacement
Uterine displacement
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