Repro 4 Flashcards
(91 cards)
1
Q
What is the percentage of abortion diagnosis that find a cause and list the 2 main causes of abortion in sheep
A
50% will not find out the cause Abortion 1) Campylobacter foetus spp foetus ○ Both Campylobacter foetus subsp foetus and Campylobacter jejuni cause abortions 2) Toxoplasma gondii
2
Q
Campylobacter feotus spp foetus what type of organism, what age are the abortions, clinical signs, abortion rates and re-infection rates
A
- Commensal organism of the in the gastrointestinal tract -> ingestion generally from carrier sheep
- Result in late-term or full term abortions
- Often no signs that ewe is about to abort
- Can develop metritis following abortion but death is uncommon in the ewe
- Abortion rates after infection is about 10-20%
- A ewe that has aborted will develop immunity to re-infection
3
Q
Campylobacter feotus spp foetus what are the short and long term management strategies
A
Management in the short term
- Removal of aborted ewes to another paddock
○ Need to be careful about moving and stressing the heavily pregnant sheep, as well as exposing more sheep and pasture contamination
- Husbandry, social grouping, stocking rates -> stress etc.
- As commensal organism so can’t just give antibiotics
Management in the long term
Vaccinate -> cooper guardian campylobacter vaccine
4
Q
What is the progesterone block and when needs to be removed
A
support gestation, immune response lowered, contraction low -> need to remove for parturition
5
Q
What are the 10 steps in the partition process
A
- Foetus grows too big for uterus, not enough nutrients -> hypoxia -> foetal stress
- Release of adrenal corticotropin hormone (ACTH) from foetal anterior pituitary
- Corticosteroid level rise (from foetal adrenal cortex)
- 1multiple similar enzymes are activated by high corticosteroids levels
- Progesterone (progestagens) are converted to Oestradiol - IMPORTANT STEP
ALSO foetal corticosteroids cause the placenta to synthesize PGF2alpha -> luteolysis - Dramatic decrease of progesterone and increase in oestradiol
- Removal of the progesterone block + high oestradiol + PGF2alpha levels -> increased myometrial contractility
- Increase myometrial contractions push the foetus closer to the cervix
- Cervical stimulation results in increased oxytocin production via Ferguson’s reflex
- Increase PGF2alpha leads to an increase in relaxin production from the CL and/or placenta
- Relaxin relaxes the pelvic ligaments and loosens the other tissues at the birth canal by softening the connective tissue, also in the cervix
ALSO have voluntary abdominal contraction to remove the foetus
6
Q
What hormone results in the lubricates the birth canal
A
Oestradiol -> increase secretion from glands in reproductive tract particularly the cervix
7
Q
What are the 4 steps in the Ferguson’s reflex
A
- Pressure on cervix (from myometrial contractions so foetus pushed closer to cervix)
- Trigger via paraventricular nucleus in the hypothalamus -> release of oxytocin
- Oxytocin into blood stream
- Leads to strong uterine contraction
8
Q
How many days after the LH surge does whelping occur and what occurs with single puppies
A
LH surge (day zero) from this point takes 65 +/- 1 day
- Single puppies -> often born of end up in a dystocia
○ Single puppy cannot produce sufficient ACTH
○ Need to do a C-section to remove however can be hard to determine when ready to be delivered
§ If test the heart rate via ultrasound and start to decrease when stressed -> should be about 240-220
9
Q
What are the 2 main things you can test for to see whether whelping is about to occur
A
1) Take rectal temperature twice per day
§ Temperature drops 8-24 hours prepartum due to loss in progesterone
2) Optional: serum progesterone assess daily in last few days
§ Progesterone drops 24-48 hours perpartum
10
Q
What are the 2 main reasons for induction of parturition and what within
A
- As a management tool
a. Synchronise calving in dairy herds
b. Embryo transfer calf
c. Batch farrowing in sows
d. Facilitate cross mothering in sows
e. Concentrate labour efforts
f. Observe parturition - For medical reasons “high risk pregnancy”
a. Undesirable pregnancy of heifer -> not sufficient weight when mating to carry the calf
b. Ruptured prepubic tendon
c. Excessive udder oedema
d. Maternal disease-> HypoCa, Preg Tox, Hydrops…
f. Prolonged gestation in cows
g. Neonatal Isoerythrolysis (NI) foals
11
Q
Compare abortions in early pregnancy vs those in mid gestation
A
Abortion (Early Pregnancy)
- Few complications
○ Early Embryonic Loss (EEL) is a ‘natural’ process
Abortion (Mid gestation)
- Complications -> hardest time due to progesterone block
○ Failure of abortion
○ Require multiple treatments
○ Risk of dystocia
○ Increased risks of
§ RFM, Metritis, Delayed uterine involution
12
Q
List 7 indications for abortion
A
- Misalliance
- Female too young
- Wrong sire
- Bred out of season- Female entering feedlot
- Reproductive pathology
- Fractured pelvis
- Ruptured prepubic tendon
- Excessive udder oedema
- Mare with twins
13
Q
What is the main thing that maintains pregnancy and list the 4 ways to reduce the activity (induce)
A
PROGESTERONE
1) Stopping production (eg Luteolysis)
2) Using it up (eg cortisol increases metabolism -> turn into oestrogens)
3) Blocking it (eg agonists block receptors)
4) Over-riding it (eg applying Oxytocin directly)
14
Q
What are the 2 main options as drugs that induce abortion or birth and how work
A
1) Corticosteroids
1. activate the enzyme that metabolise progesterone
2. cortisol metabolised cholesterol into oestradiol (less metabolised into progesterone)
2) Prostaglandin PGF2alpha -> results in luteolysis - decrease in progesterone production, also increase in myometrial contractions and release of relaxin that relaxes smooth muscle around the birth canal
15
Q
What are the 3 corticosteroids used in cattle how long is the effect
A
- Dexason/Dexapent – Dexamethasone sodium phosphate
- 30 x more anti-inflammatory effect than cortisone
- Acts for about 48 hours - Trimdexil – Dexamethasone trimethylacetate
- Medium acting
- Calving induction, ketosis - Dexafort
- Combination sodium phosphate (rapid onset) and Phenylpropionate (long acting)
- Short and long acting
- About 10 days
16
Q
What are the 2 main drug formulations used in cow abortions, when used, how long take to abort and possible risks
A
- PGF2alpha
○ 5 days after end of oestrus (comes into oestrus in 3
○ 5 days, but takes up to 10 days to abort)
○ ~100% reliable during first 3-4 months
§ To preg test or not to preg test?
○ Unreliable between 5 – 8 months gestation - PGF2alpha plus short acting corticosteroids
○ Effective between 5 – 9 months
○ Animals abort in about 5 days
○ Risk of RFMs, dystocia and metritis
17
Q
Calving induction what used for, how early can it be done, how long does it take, what is occurring in the industry and vets role
A
- An aid to management in seasonal calving herds
- Can induce cows to calve up to 4 months early
- But we want them to lactate
- Takes days-weeks
- Practice is being phased out (except for therapeutic reasons)
- In 2016, vets needed special permission to induce >15% of a herd
18
Q
What are the 2 main drugs used for calving induction and how long until calve after injection
A
Use corticosteroids
1) Short acting dexamethasone
○ Within 10 days of term, 90% calve in 45 hours +/- 5 hrs
○ PG: Calve in 1 – 4 days
2) Long acting dexamethasone
○ 25 – 30 mg Dexamethasone Trimethylacetate (Trimedexil)
○ In 2 weeks-time
§ If udder development ready to calve, give PG
§ Otherwise repeat Dex
§ Calve more quickly as pregnancy progresses
19
Q
What are the 5 main downsides of calving induction
A
- 5% decreased milk production
- High incidence of RFM -> not as bad if come back 14 days later
- Significant incidence of toxic metritis
- High calf mortality
a. stillbirths or non-viable - Reproductive performance unaltered
20
Q
Ewe abortions what are the 2 drugs used and what stage of gestation and what drug is used for ewe induction with time in which they would lamb
A
Ewe Abortion 1. PGF2alpha ○ Effective during the first 50 days of gestation 2. Corticosteroids ○ Not highly effective until late gestation Ewe Induction - Short acting corticosteroids ○ 70 – 90% lamb in 1 – 3 days ○ Efficiency declines before day 140
21
Q
Doe abortion what drug used at what stage of pregnancy
A
- PGF2alpha
○ Single dose effective throughout pregnancy at inducing abortion and parturition
22
Q
What are the 3 options for mare abortions, what needs to be done based on gestation length, which method of choice and possible side effects
A
1) PGF2alpha
○ Method of choice
○ Single injection up to day 35
○ Multiple injections up to 5 days after day 35
○ Don’t react well -> sweat, colic
2) Cervical dilation and intrauterine infusion of saline, tetracycline, dilute iodine
○ Significant risk of dystocia after 7 months
3) Manual dilation of cervix with or without oxytocin and removal of foetus not recommended after 7 months
23
Q
List 7 reasons for mare inductions and what must it involve
A
Must have severe (life threatening) risk to mare or foal 1. • Fractured pelvis 2 • Previous NI foals 3. • Ruptured prepubic tendon 4. • Repeated stillborn foals 5. • EHVI in foaling unit 6. • Not udder oedema!! 7. • Not prolonged gestation
24
Q
Mare inductions after what day of gestation and the 2 main drugs used and when foal delivered after injection
A
> 330 days of gestation
1) Oxytocin -> common
- Oxytocin 5 IU iv and 40 IU im
○ Wait 20 minutes and repeat
○ Foal normally delivered within 1 hr
○ Be in attendance with dystocia equipment
2) Prostaglandins -> not as common
- Lutalyse (dinoprost)
○ Time of onset is variable and is associated with foal deaths -> variable
- Estrumate (fluprostenol)
○ Safer but onset is still variable from 30 min to 3 hrs
25
What are the 4 main downsides of mare inductions
1. Premature placental separation
2. Maladjusted foals common
3. Fractured ribs common
4. Dystocias common
26
Sow abortion what drug used at what stage of gestation and sow induction what drug used, off-label in what species and downsides
```
Abortion
- PGF2alpha
○ Single dose effective throughout pregnancy at inducing abortion and parturition
Induction
Blocking Progesterone receptors
- Aglepristone (Alizin®)
○ Off label in other species (cat, rat, rabbit) (on label for 0-45 days in bitch)
downsides
-> expensive and MUST BE GIVEN BY A VET
```
27
Bitch abortion what is the main drug and what occurs with different gestation lengths, how many injections and induction of parturition in btich
- Aglepristone (Alizin®) is registered in Australia for induction of abortion in the bitch from 0 – 45 days after mating
○ Before about 35 days, foetus is resorbed
§ Should wait till off heat as if given then mate again 2-3 days later
○ After 35 days, they deliver the foetus -> not nice, want it to be done before this
○ 2 injections 24 hours apart
○ MUST be given by a vet
Bitch – induction of parturition
- Off-label use of Alizin
- Evidence it’s safe from day 58-59
- Takes >24h
- Pregnancy can always be terminated surgically in the dog and cat!
28
abortion in the queen what are the two main methods
1) Alizin is off-label but reported to work up to day 45
| 2) Desexing a better option in most cases!
29
Define a mammary gland, nipple/teat and udder
Mammary Gland
- A mammary gland is an organ in mammals that produces milk to feed young offspring. It is an exocrine gland that is an enlarged and modified cutaneous sweat gland, and gives mammals their name.
Nipple / Teat
- Projection of a mammary gland through which milk flows
Udder
- Another word for mammary glands – especially those that are big and baggy
30
Describe the embryology of the mammary gland
```
- Derives from Ectoderm and Mesoderm
○ Derived from skin
- Mammary Buds
- Mammary Ridges
1. mammary buds form from mammary ridges
2. Epidermal sprouts give rise to ducts and alveoli
○ One sprout ‐1 duct system
○ Multiple sprouts ‐multiple duct system
```
31
What is the teat sphincter and alvoeli
Teat sphincter -> prevent milk from being exposed to air and therefore bacteria (perfect medium for growth)
Alveoli -> milk producing units
- Cuboidal epithelial cells, myoepithelial cells - Eject the milk from the udder , capillaries
32
What are the 2 main supporting structures of the mammary gland
1) Lateral Suspensory Ligament
2) Median Suspensory Ligament - through midline of the udder from the pelvis
- Has 2 layers
○ Complete separation of right to left
○ Incomplete separation of front to back
- Rupture of suspensory ligament results in teats moving outwards and dropping of udder
33
Blood supply of the mammary gland, how many liters needed to make a liter of milk and the arterial and venous supply
```
○ 500 litres of blood to make a litre of milk
Arterial:
- External Pudendal
○ Inguinal canal
○ 1.5‐2cm diameter
○ Sigmoid flexure at inguinal canal
- Ventral Perineal
○ Pelvic canal
○ Minor contribution
Venous
- “Milk Vein”
○ (aka Superficial cranial epigastric/abdominal)
- External Pudendal vein
- (perineal vein)
“Venous ring”
- Forms during pregnancy
- Anastamoses of all veins
- Valves become incompetent
```
34
What is the lymphatic drainage tract in the mammary gland
- 2‐4 mammary Lymph nodes each side
○ “Superficial Inguinal” or “Mammary” LNs
- Then to medial iliac LNs
35
Innervation of the mammary gland what are the 3 nerves involved and what do they supply
```
- 1st and 2nd Lumbar nerves
○ Skin cranially
- Perineal Nerve
○ Skin caudally
- Genitofemoral (inguinal) nerve
○ Internal, deeper tissues
```
36
What are the gross anatomy structures from the alveoli to environment in the cow mammary gland
Secretory units(alveoli) ->
Small intralobular ducts (within lobules) ->
Larger interlobular ducts ( in interlobular septa) ->
Lactiferous ducts
Progressive increase in diameter but decrease in numbers ‐ ~ 10 enter ->
Gland sinus (cistern) - sinus = cavity ->
Teat sinus (cistern) ->
Teat canal ->
Exterior
37
What are the 4 times in a cows life in which the mammary gland changes
- Puberty
- Pregnancy
- Lactation
- Weaning (involution)
38
Puberty and pregnancy what changes with the mammary gland and why occurs
Puberty
- Cyclic effects of ovarian hormones cause development of parenchyma
- Parenchyma
Pregnancy
- Hormone increase
- more development of the secretory tissue
-> Oestrogen, adrenal steroids, GH -> make ducts grow
Progesterone and prolactin -> make alveoli form
- Commencement of lactation (prolactin and adrenal steroids result in milk secretion
- Production of colostrum in some species
39
Lactation and weaning what changes with the mammary gland and why
Lactation
- Big spike in secretory tissue
- Prolactin, TSH, GH produced at the end of pregnancy result in start of lactation
○ But progesterone inhibits lactose formation so milk isn't released by colostrum is form (providing energy and antibodies)
○ When colostrum is removed a prolactin surge occurs resulting in reflex of milk letdown -> further milk production
Involution (Regression)
- Distension of alveoli/ducts with secretion
- Loss of secretory cells and capillaries‐ apoptosis shrinkage of myoepithelial cells
- Increase leukocytes
- Contained secretions & degenerating epithelial cells phagocytosed by neutrophils and macrophages
40
Colostrum what are the 5 important composition and why
1) High in Vitamin A (because neonates are low)
2) High in Fat (for energy)
3) High in antibodies -> epitheliochorial animals unable to get across the placenta so need it orally
4) Not high in carbohydrates
○ Water follows sugar -> osmotic effect therefore would dilute the colostrum -> DON’T WANT (doesn't occur in fat)
5) High in other vitamins
41
What are the 5 components of milk
1. Carbohydrates
- Lactose (=glucose + galactose)
○ Job is to draw water in (main driver of milk volume)
- Oligosaccharides
2. Proteins
- 3.5% generally - depends on genetics
- Caseins (“curds”)
- Albumins and globulins (“whey”)
3. Fats
- Mostly triglycerides, 3-6%
- economically important
- genetic and diet affect fat content
- Not synthesised in mammary gland – they come from rumen and liver and are transported into milk by mammary epithelial cells
4. Salts
- Unimportant economically
5. Cells
- Epithelial and White cells
42
What are the 2 types of proteins in milk and the 3 classes of protein
```
2 types of proteins:
1) Caseins
§ Unique to milk
§ Insoluble
2) Whey proteins
§ Albumins
§ Globulins
§ Most economically important component of milk
3 classes]
1) Globulins
- “round proteins”
- Enzymes, antibodies, haemoglobin …
- Albumins – a low molecular weight water soluble subclass of globulin
2) Fibrous (scleroproteins)
- long protein filaments shaped like rods or wires
- structural or storage proteins
- typically inert and water‐insoluble
- Collagen, elastin, keratin
3) Membrane proteins
- attached to, or associated with the membrane of a cell or an organelle
```
43
Measuring milk quality what are the 4 considerations and things within
```
1. Normal components of milk
○ Protein
○ Fat
○ Volume
2. Abnormal components of milk
○ Cells
3. Contaminants of milk (penalties)
○ Bacteria
○ Sediment
○ Water
○ Inhibitory substances
4. Temperature (penalties if too low)
```
44
What are the 2 ways cells in milk are measured, normal values and what are the 2 types of cells within
1. Bulk Milk Cell Count (BMCC)
- Cells in the vat
- “Premium milk”
○ < 250,000 cells per ml
2. Individual Cow Cell Count (ICCC)
- Cells from an individual cow
Types of cells not differentiated when counted
○ Normal = 50,000‐250,000 cells per ml
○ In mastitis can rise to several million cells/ml
Cells in milk
1. Leucocytes
- Neutrophils
- Macrophages
- Lymphocytes
2. Epithelial Cells
- Normal shedding of the epithelial lining
45
What are the 2 main mammary gland defences against mastitis
1. Physical Barriers
- Teat canal
- Keratin Plug
2. Substances in milk
- Cells
- Antibodies
46
Milk ejection reflex "letdown" what results in this and what inhibits it
Suckling -> Nerve stimulation -> Oxytocin release -> Myopeithelial cells -> Milk Letdown
Inhibited by Adrenaline
- Blocks OT release
- Constricts capillaries
47
What are the 4 steps in the administration of a dry cow therapy
1. Ensure animals are restrained and disinfect gloves
2. Disinfect the teat ends
3. Treat all quarters
○ Do not contaminate syringe nozzle
○ Do not insert the full depth of syringe nozzle into the teat otherwise damage may occur
4. Massage syringe content out of the teat and into the quarter after instillation
48
What are the 2 steps in the administration of a teat seal and what 2 things don't you do
1. Completely disinfect teat ends
2. Treat all quarters by gently squeeze the top of teats when inserting product to encourage syringe contents to stay within the teat
○ Again do not insert the full depth of syringe nozzle into the teat
DO NOT MASSAGE THE TEAT AND UDDER
DO NOT ALLOW THEM TO LIE DOWN ON THE BARE GROUND OR SOILED AREAS for 2 hours after treatment
49
List 5 sings of impending parturition
1. Lowered body temperature
2. Behavioural changes
3. Udder/Vulval and pelvic changes
4. Progesterone levels decline
5. Calcium levels in mares milk spike
50
List 5 warning devices for mare parturiton
1. FoalApp - iPhone
2. Foaling alarms
a. Breed-Ezy -> alarm goes off when mare lays down (lots of false positives)
3. Vulval devices -> sutured into the vulva so when vulva opens the alarm goes off
4. Foaling cameras
5. Foal watch crew
51
What are the 3 general stages of partition
1. Stage I (6 - 12 hours)
- Cervical dilation, vaginal relaxation, uterine contractions
- Signs include: nesting behaviour, restlessness, shivering may vomit and or lack appetite
2. Stage II
- Starts with rupture of chorioallantois and ends in expulsion of foetus
3. Stage III
- Ends when foetal membranes are passed in their entirely
52
Mare what are the 4 signs that she is ready to give brith
- Pelvic ligaments relaxed
- Full udder; waxing
- Gestation >320 days
- Milk Ca increases 24-48 hours pre-partum
53
What are the 3 stages of birth in the mare and what occurs at each stage
Stage I (1-4hours)
- Restlessness, frequent urination, defecation, may sweat, may lay down
- The foals rotate in stage I therefore important not to intervene too early - do not stress at this stage
Stage II (5-20mins)
- Starts with rupture of chorioallantois
- Rapid explosive delivery
- If >60mins foal likely to die
Stage III
- End when foetal membranes are passed in their entirety
54
Lambing when intervene, what is important if do intervene and the 6 causes of dystocia in a flock
- Generally recommended to intervene if a ewe has been straining for over an hour with no obvious progress
- ALWAYS check for another lamb per vagina or prior to suturing uterus
Causes of dystocia in a flock
1. Abortion
2. Disproportionate size of the ewe and lamb
3. Malpresentation of the foetus
4. Failure of the cervix to dilate -> common
5. Vaginal prolapse
6. Deformed lamb
55
Farrowing what occurs with the first 2 stages of parturition in terms of clinical signs and intervals between pigs/ how long take
```
Stage I
- Sow nests about 72 hours prior
- Restless
- Pelvis drops
- About 8 hours milk spurts
- About 30mins respiratory rate increases
- Tail wags
Stage II
- Pigs appear at about 12-25minute intervals
- Farrowing takes about 3-5 hours
```
56
Kittening how long does stage II generally last and the clinical signs in other stages
Stage II
- Average duration - 8 hours; range: 4-42 hours
- Stages are the same as in the bitch
- Dystocia is uncommon
57
Whelping in the bitch what are the 3 stages in terms of clinical signs, time between pups and how long each last
Stage I (6-12 hours)
- Nesting behaviour, restlessness, vomiting, anorexia, shivering cervical dilation, vaginal relaxation, uterine contractions
Stage II (4-6 hours up to 12-24 hours in some)
- Expulsion of first pup can last up to 4 hours, usually 30min to 2 hours in between pups
- Note dark green pigment of placenta
Stage III (variable)
- Expulsion of allantochorionic foetal membrane
- may occur without immediate following stage II
58
What are the 6 important considerations when thinking about intervening during parturition
1. History - vital
2. Heads up - literally
3. Owners on standby - difficult not to intervene
4. Litigation
5. Does she really need it??? Need to be sure
6. Overdue - hard to intervene strictly on the date
59
List 6 general warning signs of dystocia and 3 ways to determine
1. Excessive straining without results
2. Haemorrhagic or foul smelling discharge
3. Excessive interval between or within stages
4. Active labour > 4 hours and no pup produced
5. Green-coloured or malodorous vaginal discharge, bleeding
6. Interval between pups > 30 min or > 2 hours (without myometrial contractions)
How to determine
1. Vaginal exam
2. Ultrasonography
3. Radiology
60
List 6 indications for surgical management (caesarean) and what 3 things need to rule out first
1. Complete, partial primary or secondary uterine inertia
2. Poor response to treatment (oxytocin and calcium)
3. Past history of dystocia or caesarean section
4. Foetal distress
5. Systemic illness of the bitch/queen
6. Suspected uterine torsion/rupture/prolapse or herniation
Need to rule out
1. Foetal oversize or malformation
2. Maternal pelvic obstruction (fractures, masses)
3. Non-reducible malpresentations
61
When to intervene with cows and the 5 risk factors for bovine dystocia include
Stage 2 - 0.5-4 hours - heifers longer
Risk factors for bovine dystocia include
1. Malposition/malpresentation
2. Limb/head flexion
3. Cervical constriction
4. Posterior presentation (breech)
5. Foetal deformities -> schistosoma, akabane
62
What are 3 farrowing intervention strategies and the rule of thumb
- Manual examination
- Oxytocin 10/U
- Caesars generally not required
- Rule of thumb: manual examination after 45 minutes after pig #7 then oxytocin
63
Stillbirths when increase risk in farrowing
- After long farrowing > 4 hours
- After long interpig interval > 40 minutes
- With gas heaters and increased CO levels
- After induced farrowing and oxytocin
- Associated with premature rupture of the cord and foetal anoxia
64
Equine intervention in stage II, stage III and dystocia intervention
Stage II
- Be aware of history
- Size generally not an issue
- Once rupture of chorioallantois expect a steady process
- Be ready to intervene if malpresentation
○ Eg neck, limb flexion, posterior presentation
- Length of limbs and muzzle make life challenging
Stage III
- Often require intervention
- Foetal membranes usually delivered within 30 - 90 min after end of stage II
- Retained when not released by 3-5 h post foaling
- NK > 4 hours - NATALIE
Dystocia intervention
- Foals tend to get stuck at the shoulders
- Be alert for warning signs: maternal/foetal distress, malodour, discolour, stasis etc.
65
Foal 'red bag' what is it, why occur and what need to do
Foal "red bag"
- Failure of cervical star to rupture at cervical pole - thinner region
- TRUE EMERGENCY
Need to rupture chorioallantois and deliver foal ASAP
66
List 3 main oestrus detection in cattle and issues
- KMAR
○ False negative - lameness (won't be mated properly)
- Tail paint
○ False negative - lameness (won't be mated properly)
○ Rubbing against objects, rain, removal of paint in any other way but mounting
- Pedometer
○ Lameness again an issue
○ Giving no information about when cows actually coming into oestrus and mounting behaviours
67
Define non-return rate, conception rate and 6 week in calf rate
Non-return rate -> % of inseminations that were not followed by a return to heat
Conception rate -> % insemination that resulted in a confirmed pregnancy
6 week in calf rate -> the percentage of herd that gets in-calf during the first 6 weeks of mating
68
What is the industry standard for earliest pregnancy diagnosis via palpation
6 weeks (industry standard) -> less risk of losing the foetus
69
List some influences of reproduction within a herd
```
- Management practices -> from all over the management
○ Conduction of AI
○ Semen storage
○ Calving themselves -> calving issues
○ Infections
○ Stress of the animal
○ Heat detection methods
- Choice of bull semen
- Choice of bull itself
- Nutrition
- Age structure of the herd
```
70
How common is the use of obstetrics in cattle, horses, pigs and sheep
```
- 3-25% in cattle
○ Most common in heifers
○ DIY or Vet call
- 1-2% in horses
○ Urgent, dramatic
- 1-2% in pigs, sheep
```
71
What are the 4 main costs to the use of obstetrics in production animals
- Millions of dollars
- Animal welfare
○ Neonatal mortality
○ Maternal mortality
- Decrease performance and increase wastage
○ For both the mother and foetus
- Labour and vet costs
○ Isn't that costly
72
What are the 4 main causes of of dystocias and the 2 sources
- Maternal
- Foetal
○ Both contribute to dystocias
1. Foeto-pelvic disproportion
2. Malpresentation
3. Ineffective labour
4. Other
73
Foeto-pelvic disproportion what are the two things that influence this and the frequency in beef and dairy cattle
- Related to both
○ Foetal birth weight - foetus too big for mother pelvis
○ Maternal body weight/conformation
§ May have small pelvic cannel, protuberance blocking
- Frequency
○ 50-70% of dystocias in beef
§ Larger than dairy due to the genetic selection of large calves that have fast growth rate
○ 15-30% in dairy cattle
○ Probably less common in other species
74
Malpresentation what contributes to this, when most dangerous and frequency in cattle and horses
```
- Cause often not known
○ Foeto-pelvic disproportion contributes
○ Foetal maturity/strength/coordination
§ Weak -> cannot pull itself up into normal calving position
- Especially in posterior presentation
○ Hindlegs or bum first
- Frequency
○ 20-45% in cattle -> common
○ Relatively common in horses
○ Less common in other species
```
75
Ineffective labor what caused by, primary and secondary causes and frequency in cattle, horses, pigs, dogs and cats
- Weak or ineffective uterine contractions
○ Primary
§ Never started to push
§ Hypocalcaemia, debility, obesity
○ Secondary
§ Started well but then declines
§ Exhaustion (obstruction, twins, hydrops)
- Frequency
○ 10-20% in cattle
○ Less common in horses
○ The most common cause in pigs, dogs, cats
§ Can be an issue with owner not detecting the uterine contractions
76
What are the 2 other common causes of dystocias and what caused by
1) Insufficient dilation
○ Cervix, vagina (generally not an issue), vulva (can get through cervix, vagina and then unable to stretch the vulva
2) Uterine torsion
- Foetal monsters
○ Bulldog calves, hydrocephalus, co-joined twins, waterbelly
○ Schistosoma reflexes, two headed
77
What are the 3 main ways to prevent dystocias
1) genetics
2) nutrition
3) management
78
How can genetics help decrease dystocxias
- Some factors can be selected for:
○ Foetal birth weight - low birth weight that has rapid growth rate
○ Double muscling - Belgian blues
○ Gestational length
§ Longer length longer time of growth for calf
○ Maternal pelvic diameter (doesn't equal hip width)
§ Cannot measure across the hips -> need to measure internal diameter of the pelvis
- Some don't respond well to selection:
○ Foetal presentation, posture, position
§ If cull on this will still get those presentations
○ Dystocia itself has low heritability - DON'T CULL BASED ON
79
How can nutrition help decrease dystocias throughout the life of a heifer
- Preweaning growth of heifers
○ Has some effect on size at puberty
○ Sets up for later production life
- Weaning to mating
○ Growth in this period affects pelvis size
- Mating to 1st parturition
○ Restriction of gestational nutrition is an imprecise way to affect foetal growth
○ Restriction of late gestational nutrition carries with it considerable risk to the dam
§ Undernourish -> May get large calves with skinny mums -> dystocia
80
How can management help decrease dystocias
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- Excessive intervention
○ Some species differences
- Delayed intervention
○ Timely intervention may prevent a minor dystocia form developing into a serious dystocia
- Frequency and expertise of observation
```
81
How to tell if a foetus is alive within the uterus
○ If facing forward can put hand over heart and feel heartbeat
○ Can also feel the pulse
○ Stick fingers around the mouth - suck reflex? Negative may not be dead, may just be stuck
○ Pinch hooves between the claws should get withdrawal - if not again may still be alive
82
What are the 5 options for the management of dystocia
1. Manipulation
2. Extraction
3. Foetotomy
4. Caesarean section
5. Euthanasia
83
Manipulation of a dystocias what can and cannot correct, what need to protect and what work with
- Correct position and postures if possible
- Don’t try to correct presentation
○ Turning posterior to anterior is unrewarding
- Minimise the diameter of the calf/foal/lamb
- Protect the uterus at all times
○ Cup hand around the foot of the calf as move
○ Use plenty of lubricant
- Use retropulsion intelligently
○ Push calf back in to get extra space - between the contractions
- Minimise maternal straining
○ Epidural (local anaesthetic into spine), tocolytic (works directly on smooth muscle of uterus to decrease
- Positioning of the patient
- Directed and appropriate traction
At an appropriate time, direction and force
84
For large animals what equipment can be used for leg and head flexions and rotation of calf
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- Leg flexions
○ Hands
○ Chains/ropes/straps
- Head flexion
○ Fingers
○ Eye hooks
○ Snare
- Rotation of calf
○ Need to be done as if go backwards, against curvature of spine, contraction of abdominal muscles and less flexibility of the pelvis
○ Directed traction
○ Manual leverage
○ Detorsion rod
○ Pulley system
```
85
Extraction in the correction of dystociates when use, how to tell if it will fit
- When there is no physical obstruction to passage of the foetus
- When foeto-pelvic disproportion has been assessed
- How hard should you pull?
○ Not too hard
- How do you tell if it will fit?
○ Both front feet out of vulva and head at the pelvic canal
○ Back legs up, both hooks out of vulva
86
During extraction what must do first and equipment used for large animals
- Correct any malpresentations FIRST
- Place chains/ropes properly
- Orientate the foetus
- Dilate the cervix
Large animal equipment
○ Chains, ropes, straps
○ Eye-hooks, snares
§ Don't use in lambs or fawns
○ Pig puller
§ Can clamp the head of the fawn and lamb
○ Calving jack
○ Pulleys
§ Hard to use in a paddock
○ Ropes
87
Episiotomy what used for and what species used in
```
○ Used to enlarge Vulval opening
§ Avoids uncontrolled testing
§ Vulva dilation often feasible
§ Prevent rectal-vaginal fistula
○ Occasionally useful in cattle
○ Rarely used in dogs/cats
```
88
Foetotomy how can it help reduce dystocias, when use, what should do instead and the two types
- reduction of foetal size by dissection
- Indications
○ Dead calf
○ Alternative to correction of difficult flexions
- INSTEAD JUST DO A CASEAR
Total vs partial
○ Partial is just cutting a limb or head off
○ Total -> multiple limbs, splitting pelvis, cut the head
Percutaneous vs subcutaneous
89
Percutaneous vs subcutaneous what are the differences and advantages and disadvantages
Subcutaneous -> skin the forelimb then pull off the body
- Advantages
○ Relatively quick
○ No cutting of bone
○ Retain a traction point
- Disadvantages
○ Limited in application
○ Not so easy in fresh foetuses
Percutaneous - saw the limb, head, pelvis, etc.
- Advantages
○ Flexible… almost unlimited range of cuts
○ Simple cuts can be quick
- Disadvantages
○ Usually leaves sharp edges of bone - laceration risk to the cow
○ Loss of traction points
○ Technically demanding; specialised equipment
○ Can be frustrating and physically challenging
90
List some indications for Caesarean section and the 2 surgical approaches
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- Indications
○ Unable to extract foetus per vaginal
○ Live/viable foetus(es)
○ Valuable foetus(es)
○ Elective pre-parturient
○ Foetal monsters
○ Dead, emphysematous foetus(es)
○ Uterine torsion
- Surgical approaches
○ Standing (cattle)
§ Left flank
§ Right flank
○ Recumbent and all small animals
§ Flank
§ Paramedian
§ Ventral midline
```
91
Euhanasia in the management of dystocias when use
- Sometimes is the best option
○ Animal welfare
§ Already a disaster
○ Cost
