637 - Obstetrics Flashcards
(121 cards)
1
Q
What are the signs of pre-calving?
A
Enlarged vulva
Mucous plug
Enlarged udder (bagging up)
2
Q
How long is stage 1 labour in a cow vs a heifer?
A
2-6 hours in cows
Up to 24 hours in a heifer
3
Q
Describe stage 1 labour including behaviour and changes to the cow.
A
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
4
Q
What triggers the cow to progress from stage 1 to stage 2 labour?
A
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.
5
Q
How long until calving usually occurs once cervical dilation is initiated?
A
24 hours, but sometimes as little as 6 hours in mature cows
6
Q
During stage 2 labour in cattle, how can you differentiate between amnion and allantochorion?
A
Amnion = white, contains thick/viscous + very slippery fluid
Allantochorion = reddish, contains watery yellow to reddish/purple fluid
7
Q
How can you determine the status of the cervix in obstetrical cases?
A
Speculum exam or manual palpation
8
Q
How long is a normal stage 2 labour in a cow vs a heifer?
A
Cow - 2 hours
Heifer - up to 4 hours
9
Q
In how many hours should stage 3 be complete in a cow?
A
8-12 hours
Anything more than 12 hours is considered a retained foetal membrane (RFM)
10
Q
In how many hours should stage 3 be complete in a mare?
A
3 hours
11
Q
Name the 3Ps of foetal disposition.
A
- Presentation
- Position
- Posture
12
Q
At what point should you intervene and assist in parturition during stage 1 activities?
A
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
13
Q
When should you intervene and assist in parturition for a cow in stage 2 parturition?
A
- 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
14
Q
Does epidural anaesthesia prevent involuntary myometrial contractions?
A
NO
It does prevent voluntary tenesmus though
15
Q
What sort of things could cause a foetus to not enter the birth canal at all?
A
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
16
Q
Describe the consequences/effects of dystocia on a farm.
A
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
17
Q
What are the targets for beef herds in terms of dystocia rates for cows and heifers?
A
Cows <1% dystocia
Heifers <5% dystocia
18
Q
Describe the general approach to obstetrics cases.
A
- 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
19
Q
What abnormalities on physical exam might you pick up in an obstetrics case?
A
Overconditioning - BCS >4 or <2.5
Recumbent animals - dec. rumen sounds
Exhaustion, calving paralysis, hypocalcaemia
Mucous membrane pallor
Discharge from birth canal
20
Q
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?
A
Meconium staining indicates foetal distress, and and a degree of hypoxia
21
Q
Which 2 conditions require rectal examination to diagnose?
A
Uterine torsion
Uterine rupture
22
Q
What is your next decision-making step if a calf in a dystocia has abnormal PPP?
A
Mutate and then apply traction
23
Q
What is your next step if a calf with abnormal PPP cannot be mutated?
A
Check if its alive
If alive –> C-section
If dead –> fetotomy
24
Q
Which metabolic causes of primary intertia are most common in dairy vs beef cows?
A
Dairy - hypocalcaemia
Beef - severe malnutrition
25
What ecbolics are indicated in the case of weak labour during the expulsion phase?
Calcium supplement +/- phosphorus, magnesium and dextrose
Oxytocin
26
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
27
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
28
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
29
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
30
Discuss treatment for uterine torsion.
1. Manual correction per vaginum
2. Roll the cow around the uterus +/- per vaginum manipulation, plank
3. Surgery - intra-abdominal correction but risk rupture
31
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
32
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
33
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
34
Traction should only be applied when the cow is WHAT?
Assisting with abdominal contractions
(when she's pushing)
35
We only use traction when?
The foetus is in normal PPP
36
In what situations is there a reduced chance for delivery by traction?
1. If the dam has not been able to spontaneously delivery the foetal head into the pelvis after a prolonged period of labour
2. Foetus in birth canal with forelimbs crossed
3. Hooves are rotated with their ventral surface directed medially
4. Foetus so tightly lodged in birth canal that it does not move when the abdominal press is applied
37
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
38
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
39
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
40
Discuss how to assist in the birth of a calf in anterior presentation.
1. Position the head + extend forelimbs within pelvic cavity
2. Determine whether continued traction is warranted by vaginal exam
3. Apply/pump additional lubricant around the calf
4. Apply traction to the left forelimb of the foetus until the shoulder is brought past the pelvic inlet
5. Confirm that the L shoulder has passed the ileum - fetlock joint will protrude 10-15cm past the vulva
6. Apply traction to the right forelimb until the shoulder is brought past the pelvic inlet
7. Apply traction simultaneously to both forelimbs caudally and slightly ventrally until the head emerges from the birth canal
8. 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
9. When the thorax is free, stimulate the calf to breathe by clearing mucous from nostrils and tickling the nostrils
10. Continue traction on both limbs in caudal and slightly dorsal direction when the calf is breathing
Only apply traction when the dam is pushing
41
How should you proceed if the calf hip locks despite the correct technique being used?
1. Suspend traction and stimulate breathing if the calf is alive
2. Try to palpate the foetal hind part and determine degree of rotation
3. If insufficient rotation then repel and attempt to rotate manually
4. Apply traction in a caudal and slightly dorsal direction along with abdominal contractions
5. If still not successful then pull the foetus sharply around toward the dam's flank
42
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
43
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
44
List 5 foetal causes of dystocia.
Malpresentation
Foetal oversize
Twins
Foetal monsters
Calf breed
Calf sex
Calf birth weight
45
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
46
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
47
What is mutation?
Restoration of a foetus to normal presentation, position, and posture by repulsion and rotation, version, or extension of extremities
48
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
49
What is the dose rate for a low epidural in a cow?
1ml/100kg
50
What is the dose rate for an epidural in a mare?
6-8ml/450kg
51
What is the dose rate for an epidural in a ewe or doe?
1ml/50kg
52
You are assisting a calving. You can see 2 legs and a head but the muzzle is at the same level as the left forelimb. The right forelimb is 10cm ahead of the left. What is happening and how do you fix it?
Elbow lock of the left forelimb
Correct by retropulsing the shoulder while pulling the distal limb forward by the foot.
53
How do you reposition the head in a calf with head deviation?
Grasp the muzzle or place either a war bridle or eye hooks and then retropulse the calf to allow room to bring the head around
54
Under what circumstances should a fetotomy be performed?
The foetus is dead
The foetus is emphysematous, which dec. survival rate after a c-section
There is feto-maternal disproportion/size mismatch
The foetus has an abnormality that will not allow it to be delivered
The cervix is very well dilated
55
Name the 2 fetotomy methods.
1. Percutaneous - cutting through the skin and all tissues
2. Subcutaneous - undermine the skin and then cut with the wire
56
Which situation warrants a partial fetotomy?
Malpositioning or malposturing of the foetus
57
Which situation warrants a complete fetotomy?
Feto-maternal disproportion
58
What are the ways we can reduce the risk of uterine trauma when doing a fetotomy?
Tocolytics for uterine relaxation - clenbuterol
Secure the fetotome to the foetus to reduce movement
Shield the head of the fetotome
Hold the base of the fetotome
Use reverse cuts
Use good quality instruments and fresh, sharp wire
Lots of lube (lube is your friend)
59
How much wire should you have for a fetotomy?
Arm length + the length of the fetotome x4.5
60
List the cut sequence in a percutaneous reverse-cut fetotomy for a calf in anterior presentation.
1. Decapitation + neck amputation - then attempt to deliver calf
2. Thoracic cut
3. Evisceration
4. Abdominal cut
5. Pelvic bisection
61
Describe monitoring for the dam post-calving.
Water access
Pain management
Expulsion of foetal membranes
Uterine prolapse
Any signs of trauma, sepsis, metabolic disorders, nerve damage
62
List 4 causes of uterine prolapse.
1. Dystocia
2. Tenesmus
3. Uterine atony
4. Hypocalcaemia
63
Discuss treatment of a cow with uterine prolapse.
Keep the cow quiet
Clean exposed uterus + keep moist with warm water containing 1% iodine and a clean towel or sheet
If possible, elevate the uterus to the level of the ischium or higher to relieve vascular compromise + subsequent oedema + to lessen the chance of injury
Assess if the cow is in hypocalcaemia or shock
Give an epidural
Position the cow to utilise gravity - front end downhill, hip slings, hoisting
Elevate the uterus to the level of the ischium (at least)
Gently and thoroughly clean debris + dirt off uterine surface + placenta
Slowly start kneading and pushing in the uterus from the cervical end nearest the vulva - use lots of lube, and cupped hands technique
Use hand and arm pressure to evert the horn once fully back inside the cow
Place a retention suture - Buhner's stitch
Give oxytocin
Supportive care - food, water, environment, calcium, antibiotics, NSAIDs
64
What accounts for up to 50% of all calf deaths?
Dystocia and subsequent health events
65
Discuss the consequences of dystocia on the calf.
Dec. ability to perform tasks for survival - standing, walking, suckling colostrum
Inflammation, injury
Inability to maintain homeostasis
Hypoxia + acidosis
66
Describe the consequences of improper assistance + excessive force when assisting in a calving.
Foetal blood loss
Premature umbilical cord rupture --> acidosis
67
List some post-mortem signs that would indicate dystocia.
Bloat line
Trauma - fractures
68
What is a VIGOR score?
A scoring system used to evaluate risk of perinatal mortality in calves by checking important body system functionality.
V = visual appearance of calf (swollen head or tongue, meconium staining)
I = initiation of movement after birth
G = general responsiveness to stimuli
O = oxygenation of the calf, MM colour, BP, CRT
R = rates, HR + RR
69
How much colostrum does a calf need?
10% BW within 12 hours of birth
70
List the 8 steps of calf resuscitation + early care.
1. Clear airway - sternal recumbency in first 30 seconds, remove foetal membranes + fluid from calf's mouth and nose, +/- intubate if moribund
2. Stimulate respiration - rub them down vigorously, stimulate gasping reflex,
3. Cardiac stimulation if profoundly bradycardic - give epinephrine + assist ventilation
4. Check for trauma
5. Check for swelling - nutritional support, NSAIDs, furosemide or mannitol
6. Care of umbilicus - mild antiseptic, maintain maternity pen hygiene
7. Thermal - dry the calf thoroughly, blankets, bedding, heaters
8. Colostrum
71
What is an episiotomy?
Surgical incision of the vulva and vestibulum to avoid blunt tearing of the perineum when there is either foetal oversize or insufficient relaxation during parturition.
72
Describe the surgical technique of an episiotomy.
1. Epidural anaesthetic
2. Take a scalpel and make a dorsolateral full thickness incision at the 11 or 1 o'clock position of the vulva (not horizontal or vertical exactly) - make sure you go through all vestibular tissues
3. Deliver the calf
4. 3 layer closure - mucosa, muscles + skin
5. Antibiotics and NSAIDs
73
A cow has a full thickness laceration of the vestibulum and vulva. What is the classification of this perineal laceration?
Second degree
74
A cow just calved has superficial wounds to her vulva at the dorsal commissure. What is the classification of this perineal laceration?
First degree
75
A cow has a perineal laceration involving the vagina and rectum. What is the classification?
Third degree
76
How do you treat a first degree perineal laceration?
NSAIDs
Topical antiseptic
+/- antibiotics if deeper contusions
77
Discuss the treatment of a second degree perineal laceration.
Debride dead + devitalised tissue - determine if surgical closure is possible (repair immediately if possible)
Epidural anaesthetic + surgical prep of site
Eliminate dead space with buried absorbable sutures if possible
Suture the edge of the wounds with a continuous suture pattern - absorbable for mucosa, non-absorbable for skin
Systemic ABs + NSAIDs
78
You get a call from a farmer who has a cow that recently calved and she now has a large volume of bright red blood coming from her vulva. What are your immediate instructions and then treatment when you arrive?
Tell the farmer to wash their hands and the perineum of the cow
Put their hand into the vulva and try to find where it's gushing from and hold it off until you arrive
Once you arrive attempt to clamp the vessel, ligation can be attempted but is risky if you stick the needle back into the artery
79
How do you treat a third degree perineal laceration?
6 weeks of NSAIDs and antibiotics then attempt surgical repair
80
What are the 6 major indications of a caesarean in the cow?
1. Fetomaternal disproportion
2. Incomplete dilation of the cervix
3. Uterine torsion where attempts to correct it have failed
4. Fetal monsters
5. Faulty fetal disposition (PPP) resistant to correction per vaginum
6. Fetal emphysema
81
How long do you have to make a decision to go to c-section?
20-30 minutes maximum
82
What are the potential short term post-caesarian complications?
Peritonitis
Seroma formation
Retained foetal membranes
Metritis + endometritis
Suture dehiscence
Subcutaneous emphysema
Cow death
83
What are the potential long term post-caesarian complications?
Adhesions
Low fertility
Low production
Fatty liver
Mastitis
84
What factors affect the outcome of a caesarian section?
Rapid clinical assessment in <20 mins
Condition of the cow at the time of surgery
Whether it is an elective or emergency procedure
Excessive manipulations by the owner + vet without making progress
85
Name the 6 surgical approaches for caesarians in cows.
1. Flank - standing or R lateral recumbency
2. Oblique
3. Extreme paramedian
4. Paramedian
5. Median
6. Paralumbar - standing
86
What are the pros and cons of the standing paralumbar approach for a caesarian?
Pros - less assistance required, avoids the udder + associated vasculature, minimal tension on the suture line
Cons - need to make sure the cow stays standing (first time calvers are likely to go down), contamination of peritoneal cavity with uterine contents likely, need physical strength to maneuver uterus to L paralumbar fossa
87
Describe the appropriate anaesthetic technique and other medical management for a standing caesarian.
Low/caudal epidural with lignocaine and/or xylazine 0.03mg/kg BW
Paravertebral block, inverted L, line infiltration - local anaesthesia
Clenbuterol 0.3mg/kg for uterine relaxation - reverse post-procedure with oxytocin
Avoid sedation if possible - if you need to use try to keep it light
88
Describe the appropriate anaesthetic technique and other medical management for a recumbent caesarian.
Xylazine for sedation 0.1mg/kg IV or 0.2mg/kg IM
Low or high epidural block
Local anaesthesia - paravertebral blocks, inverted L, line infiltration block
Clenbuterol 0.3mg/kg for uterine relaxation - reverse post-procedure with oxytocin
89
How large is the incision used in a left oblique approach caesarian?
30-40cm long on a 45 degree angle
10cm cranial and 10cm ventral to tuber coxae, ending 3cm caudal to last rib
90
Name the muscle layers incised through in a left oblique approach caesarian.
Cutaneous
External abdominal oblique
Internal abdominal oblique
Transverse abdominus
91
What do larger volumes of peritoneal fluid during a caesarian indicate?
Prolonged dystocia, uterine infection, uterine torsion or rupture
92
Where should the incision into the uterus be made during a caesarian?
On the greater curvature over the calf's leg (but don't cut into the leg), avoiding the broad ligament and placentomes
93
Describe the pattern, suture material and size, and technique used to close the uterus during a caesarian.
Utrecht pattern = partial thickness oblique continuous inverting
2 or 3 USP absorbable suture material
Best to do a double row of sutures although 1 is adequate
94
In how many layers do you close the muscle layers of the abdominal cavity during a caesarian?
2 layers - simple continuous pattern
First close the peritoneum and transverse abdominal muscle
Second close the internal and external abdominal oblique muscles including the transverse abdominus into some of the bites
Can infuse antibiotics between suture layers
95
What is the ideal method of skin layer closure for a caesarian?
Ford interlocking, simple interrupted, horizontal mattress or cruciate pattern
Cutting needle with non-absorbable suture material - nylon
Place 1-2 interrupted sutures at the ventral end to facilitate drainage and/or wound flushing in the case of sepsis
96
Describe the post-op care of the dam after a caesarian.
20-40IU oxytocin
3-5d course of antibiotics
NSAIDs
2-3L hypertonic NaCl if they look a bit hypovolaemic
Calcium borogluconate if needed
Monitor demeanour, temp, appetite, faecal consistency
97
Explain the prognosis after having a caesarian.
Px better for elective surgeries
Maternal survival 90-98%
Calf mortality 12%
98
Above what level is there a good passive immunity in calves (not a failure of passive transfer)?
5.2g/dl
99
What percentage of herd genetics does the sires over the last 3 generations determine?
87%
100
What is the most well noted predictor of dystocia?
High calf birth weight
101
Name 3 breeds that are at a high risk for assisted calvings and dystocia.
Limousin, charolais, simmental, Belgian Blue
102
Which breed is a low risk for assisted calvings and dystocia?
Jersey
103
Name 3 breeds which are moderate risk for assisted calving and dystocia.
Holstein, murray grey, angus, hereford, poll hereford, red poll
104
How does BreedPlan work?
Uses estimated breeding values (EBVs) which take into account phenotypic data, heritability + interbreed and inter-cohort relationships to compare/benchmark individual sires or dams to a group average for that particular trait
105
Can you use BreedPlan to compare different breeds of cow?
No - its only useful for comparison within a breed
106
Which 3 BreedPlan indices are the most important for estimating dystocia risk?
Birth weight
Calving ease (direct and daughters)
Gestation length
107
If trying to decrease the risk of dystocia - is a small or higher birth weight EBV more favourable?
Small or moderate is more favourable
108
If trying to decrease the risk of dystocia - is a lower or higher gestation length EBV more favourable?
Lower/more negative is more favourable
109
What bull conformation features contribute to dystocia risk?
Muscling
Pelvis shape
Shoulders
110
What heifer factors contribute to dystocia risk?
EBVs
Age at mating
Mating weight
Conformation
Nutrition
111
Discuss the pros and cons of early age breeding (12-15 months) for heifers.
Pros - 0.7 more calves in a lifetime, early culling of poor breeders, faster genetic improvement
Cons - lower fertility in puberty, smaller size with reference to bulls, higher dystocia risk, 5-8% lighter calves, need to supplement and have good nutritional management constantly
112
What is the maternal target for mating weight in early age heifer breeding?
60-65% mature cow weight
113
What are the components of a heifer pre-breeding exam?
Visual and rectal exam
Look at conformation - pelvis shape and area, avoid high set tails, funnel pelvis, narrow pelvis, shoulders
Pelvimetry
114
What is the optimal BCS for heifers and cows to achieve optimal birth weights and reduce dystocia risk?
Heifers 3-3.5
Cows 2.5-3 (considering possible lactation energy requirements)
115
Describe the sequelae of overfatness in calving heifers and cows.
Fat in birth canal narrows the passage
Inc. intramuscular fat limits myometrial contractility
Fat absorbs hormones that control parturition
Increased calf birth weights --> larger calves coming through a narrowed birth canal (BAD)
116
What are the herd targets for dystocia in heifers?
<5% dystocia
<2% heifer mortality
117
What are the herd targets for dystocia in cows?
<1% dystocia
0% cow mortality
118
Discuss the strategies available for managing high-risk pregnancies to avoid dystocia and losses.
Pre-term termination/abortion
Induce calving slightly earlier than due date - will get smaller calves though and need close monitoring + well-prepared producers
Elective caesarian after pred or dex + PGF injection to mature the foetus
119
Discuss the "costs" of dystocia.
Treatment
Monitoring the calving mob
Calf and/or dam mortality
Production loss through reduced dam fertility and reduced weaning weight
Loss of genetics
120
Discuss the impacts of dystocia on heifers in terms of the production losses.
15% lower pregnancy rates
Calve 15 days later than the herd
Lighter calf to weaning
30% of caesarian cases will not be able to re-conceive
121
Explain the overall benefits of using fixed time artificial insemination over natural service for beef or dairy production.
Reduced dystocia rates and lower cow and calf mortality
Long-term improvement in fertility - as they calve earlier so have a longer time for uterine involution before the next pregnancy
Increased weaning weights = more profits
Genetic benefits from using superior sire semen
