637 - Obstetrics Flashcards
What are the signs of pre-calving?
Enlarged vulva
Mucous plug
Enlarged udder (bagging up)
How long is stage 1 labour in a cow vs a heifer?
2-6 hours in cows
Up to 24 hours in a heifer
Describe stage 1 labour including behaviour and changes to the cow.
Udder full, vulva distended, softening of cervix + vulva, relaxed pelvic ligaments, cervical dilation.
Restless behaviour including walking, transitioning from laying to standing, kicking at belly, vocalisation, tail raising, frequent urination, sniffing at the ground
What triggers the cow to progress from stage 1 to stage 2 labour?
Mechanical stretching of the cervix –> Ferguson response (when a portion of the foetus enters the cervix + applies mechanical pressure from within the canal)
This is also known as complete cervical effacement.
How long until calving usually occurs once cervical dilation is initiated?
24 hours, but sometimes as little as 6 hours in mature cows
During stage 2 labour in cattle, how can you differentiate between amnion and allantochorion?
Amnion = white, contains thick/viscous + very slippery fluid
Allantochorion = reddish, contains watery yellow to reddish/purple fluid
How can you determine the status of the cervix in obstetrical cases?
Speculum exam or manual palpation
How long is a normal stage 2 labour in a cow vs a heifer?
Cow - 2 hours
Heifer - up to 4 hours
In how many hours should stage 3 be complete in a cow?
8-12 hours
Anything more than 12 hours is considered a retained foetal membrane (RFM)
In how many hours should stage 3 be complete in a mare?
3 hours
Name the 3Ps of foetal disposition.
- Presentation
- Position
- Posture
At what point should you intervene and assist in parturition during stage 1 activities?
If no progression to stage 2 after 4 hours in cows (longer in heifers) then you need to examine and see what’s going on - do a vaginal exam as a minimum
When should you intervene and assist in parturition for a cow in stage 2 parturition?
- If allantochorion has been visible for >2 hours with no progress
- No progress after >30 mins of strong abdominal contractions
- > 1 hour after feet appear with no progress
- If signs of stress or fatigue become evident - swollen tongue in calf, meconium staining, bleeding from rectum of cow, foetus visible but then dropped back
- If you suspect abnormal PPP
Does epidural anaesthesia prevent involuntary myometrial contractions?
NO
It does prevent voluntary tenesmus though
What sort of things could cause a foetus to not enter the birth canal at all?
Transverse position of the foetus in the uterus or other very abnormal PPP
Primary intertia - hypocalcaemia, severe malnutrition
Uterine torsion
Animal not in labour
Cervical fibrosis
Congenital abnormalities
No oxytocin release
Describe the consequences/effects of dystocia on a farm.
Inc. calf + dam death losses/culling rates
Inc. number of days open –> dec. fertility
Dec. milk yield (especially in the first 30 days in milk)
Inc. likelihood of future calving problems
Economic losses - calf loss, treatment cost, production loss, loss in reproductive performance, inc. culling + replacement costs
What are the targets for beef herds in terms of dystocia rates for cows and heifers?
Cows <1% dystocia
Heifers <5% dystocia
Describe the general approach to obstetrics cases.
- History - management, previous occurrances, bulls vs AI mating, breed of sire, gestation length, duration of labour, any attempts to correct? What does the client think is happening?
- Restraint - give yourself room to cast appropriately if needed
- Exam - physical + vaginal, +/- rectal exam, imaging
- Anaesthesia
- Management options - medical, vaginal delivery, fetotomy, caesarian
- Post-partum - cow + calf exam
What abnormalities on physical exam might you pick up in an obstetrics case?
Overconditioning - BCS >4 or <2.5
Recumbent animals - dec. rumen sounds
Exhaustion, calving paralysis, hypocalcaemia
Mucous membrane pallor
Discharge from birth canal
You go out to see a cow who’s having trouble calving, and see a yellow-brown discharge from the vulva - what’s happening to the calf?
Meconium staining indicates foetal distress, and and a degree of hypoxia
Which 2 conditions require rectal examination to diagnose?
Uterine torsion
Uterine rupture
What is your next decision-making step if a calf in a dystocia has abnormal PPP?
Mutate and then apply traction
What is your next step if a calf with abnormal PPP cannot be mutated?
Check if its alive
If alive –> C-section
If dead –> fetotomy
Which metabolic causes of primary intertia are most common in dairy vs beef cows?
Dairy - hypocalcaemia
Beef - severe malnutrition
What ecbolics are indicated in the case of weak labour during the expulsion phase?
Calcium supplement +/- phosphorus, magnesium and dextrose
Oxytocin
What is hydrops?
A malfunction of the uterus or placenta resulting in abnormally increased production and accumulation of interstitial fluid in either one or both of the foetal compartments - hydrops amnion is accumulation in the amnionic sac, hydrallantois is accumulation in the allantoic sac
Of the 2 types of hydrops which has a better outlook for future fertility?
Hydrops amnion as it was a congenital issue not due to uterine pathology
Describe the clinical signs that may be associated with a uterine torsion.
Vague
Restlessness, looking uncomfortable but not getting on with it, straining
No progress to stage 2 labour
Not eating
Vaginal discharge
Vulva sunken + drawn into pelvis
Explain how to diagnose uterine torsion.
Vaginal exam - tight spiralling folds, wont feel if torsion is cranial to cervix
Rectal exam - broad ligament tight band running dorsally
Discuss treatment for uterine torsion.
- Manual correction per vaginum
- Roll the cow around the uterus +/- per vaginum manipulation, plank
- Surgery - intra-abdominal correction but risk rupture
You are called out to assist a calf in anterior position. How can you assess its viability? Can you confirm it is alive?
Withdrawal reflex
Suck reflex
Corneal reflex
Cannot confirm that its alive unless you have go-go-gadget arms and can check for an umbilical pulse
You are called out to assist a calf in posterior position and want to check if its alive? How?
Anal reflex
Umbilical pulse
Withdrawal reflex
What amount of force is required to deliver a foetus in normal felivery?
70kg force
40% from uterine contraction
60% from active abdominal tenesmus + pressure
Traction should only be applied when the cow is WHAT?
Assisting with abdominal contractions
(when she’s pushing)
We only use traction when?
The foetus is in normal PPP
In what situations is there a reduced chance for delivery by traction?
- If the dam has not been able to spontaneously delivery the foetal head into the pelvis after a prolonged period of labour
- Foetus in birth canal with forelimbs crossed
- Hooves are rotated with their ventral surface directed medially
- Foetus so tightly lodged in birth canal that it does not move when the abdominal press is applied
What are the potential consequences of using excessive force to pull a foetus?
Fractures of the legs, ribs, vertebrae of the foetus
Maternal obstetric paralysis
Pelvic or hip fractures of the dam
Soft tissue tears of the birth canal
List off the necessary equipment needed for a basic obstetrics case.
Bucket - water, soap
LUBE
Chains and handles
Stomach pump and tube
Ropes
Head snare
Long sleeve obstet gloves
Nitrile hand gloves
Towels
Calf jack or pulleys (what ever you prefer/have access to)
+/- c-section gear
Describe the appropriate positioning of chains onto a foetus forelimb.
Loop of the chain above the fetlock and a half-hitch around the pastern
Apply traction to the DORSAL aspect of the limb
Discuss how to assist in the birth of a calf in anterior presentation.
- Position the head + extend forelimbs within pelvic cavity
- Determine whether continued traction is warranted by vaginal exam
- Apply/pump additional lubricant around the calf
- Apply traction to the left forelimb of the foetus until the shoulder is brought past the pelvic inlet
- Confirm that the L shoulder has passed the ileum - fetlock joint will protrude 10-15cm past the vulva
- Apply traction to the right forelimb until the shoulder is brought past the pelvic inlet
- Apply traction simultaneously to both forelimbs caudally and slightly ventrally until the head emerges from the birth canal
- Rotate the calf to dorsoilial position - begin rotating the foetus as soon as the head emerges from the vulva, need to go 180 degrees to obtain the necessary 60-90 degree rotation of the hind end
- When the thorax is free, stimulate the calf to breathe by clearing mucous from nostrils and tickling the nostrils
- Continue traction on both limbs in caudal and slightly dorsal direction when the calf is breathing
Only apply traction when the dam is pushing
How should you proceed if the calf hip locks despite the correct technique being used?
- Suspend traction and stimulate breathing if the calf is alive
- Try to palpate the foetal hind part and determine degree of rotation
- If insufficient rotation then repel and attempt to rotate manually
- Apply traction in a caudal and slightly dorsal direction along with abdominal contractions
- If still not successful then pull the foetus sharply around toward the dam’s flank
How does your decision making change when the calf is in caudal presentation?
Earlier decision to perform a c-section - if no progress for 10 minutes with traction
In what position do you need to rotate the calf to facilitate delivery in caudal presentation and in what direction should traction be applied?
Rotate calf into dorso-ilial position - twist/cross the hindlimbs
Apply caudal and slightly dorsal traction
Once the hips pass the pelvic inlet you can rotate the calf back into dorsosacral and apply caudal + slightly ventral traction
List 5 foetal causes of dystocia.
Malpresentation
Foetal oversize
Twins
Foetal monsters
Calf breed
Calf sex
Calf birth weight
What are some of the consequences of twinning in cattle?
Higher incidence of metabolic diseases - hypocalcaemia, preg tox, ketosis
Inc. proportion of dystocias (44%)
Inc. calf mortality rate (22%)
Freemartinism
Higher incidence of RFM
Low reproductive performance
You receive a call from a farmer who is concerned because one of his cows has intestines hanging out of her birth canal. What are your top 2 differentials?
Foetal monster - schistosomus reflexus
Complete uterine tear
What is mutation?
Restoration of a foetus to normal presentation, position, and posture by repulsion and rotation, version, or extension of extremities
What additional therapies must you use when mutating a foetus?
LUBE that birth canal and foetus up
Epidural anaesthetic to abolish abdominal straining
Clenbuterol to relax the uterine musculature