Infertility and obstetrics cattle/ruminants Flashcards
1
Q
What does superfecundation mean
A
Offspring born from more than one sire
2
Q
What does superfetation mean
A
fetuses developing and born at different stages; doesn’t really happen
3
Q
What is the biggest cause of no offspring from a mating
A
Early embryonic death
4
Q
Fetal mummification
A
Often no bacterial contamination
Resorption of fetal fluids
5
Q
Fetal maceration
A
Fetal death with bacterial contamination so get decay in utero
6
Q
Emphysematous fetus
A
When there is death at a late stage of gestation; e.g neglected dystocia
-> Decomposition produces gas which causes emphysema of fetal tissues
7
Q
Which type of hydrops is more common
A
Allantois
8
Q
Treating hydrops uteri in cattle
A
Depends on value of calf vs cow
- May do elective c section
- May just leave her; but be prepared to assist in parturition due to likely uterine inertia
- Can induce birth; but risk of calf death due to prematurity
- Can drain fluid; but will re-fill + risk of infection
9
Q
What do we worry about when inducing birth of a calf
A
Won’t have functioning adrenal glands
10
Q
How do we induce birth at different stages of cattle gestation
A
Up to day 100/150: CL is providing progesterone so can use PGF2alpha
From day 150-270: placenta is providing progesterone so need corticosteroids
11
Q
Risk factors for vaginal and cervical prolapses
A
Older, multiparous animals: more relaxation of pelvic ligaments
Ruminal distension
Increased intra-abdominal pressure e.g due to straw within rumen
Oestrogens in diet (white clover)
Breed e/g Herefords
12
Q
Risk of dystocia in bovine parturition
A
3-10%
13
Q
Parturition stages in cattle and timings of it
A
1) Preparatory stage: 2-6 hours
- Calf rotates to an upright position; uterine contractions begin and amnion is expelled
2) Foetal expulsion: 30 mins to 4 hours
-3) Expulsion of fetal membranes: 2-8 hours
14
Q
Most common causes of dystocia in cattle
A
Main one = feto-maternal disproportion
Then fetal maldisposition
15
Q
What does presentation mean in relation to birth position
A
Relationship between longitudinal axis of fetus and birth canal e.g anterior or posterior
16
Q
What does position mean in relation to birth position
A
Which birth canal surface is fetal spine applied to e.g dorsal or ventral
17
Q
What does posture mean in relation to birth position
A
Disposition of limbs of the fetus e.g extended or flexed
18
Q
Which drugs might be given during a dystocia case
A
Xylazine for sedation
Clenbuterol to reduce myometrial contraction strength (NB: will counteract the increased contractions caused by xylazine)
Denaverine: antispasmodic; promotes dilation of birth canal
19
Q
When would we NOT use denaverine (anti-spasmodic) in dystocia
A
With mechanical obstruction of birth canal e.g oversized fetus, uterine torsion, fetal maldisposition
20
Q
How to distinguish fore and hindlimbs when palpating fetus
A
Forelimb fetlock and carpus bend in the same direction
Hindlimb joints bend in opposite directions to each other
21
Q
What additional signs of fetal life can we look at in a posterior presenting calf
A
Anal reflex, umbilical artery pulse
22
Q
what do we describe as the maxmum pull that should be applied to a fetus during traction
A
Well coordinated pull of 4 average people
23
Q
What is the most common MATERNAL cause of dystocia
A
Uterine inertia
Due to hypocalcaemia/magnesaemia; overstretching of myometrium e.g in hydrops, fatty infiltration of uterus, hormones
OR may be SECONDARY e.g to exhaustion
24
Q
In what breed is normal delivery not usually possible due to inadequate size of birth canal
A
Belgian blue
25
Why might we see incomplete dilation of cervix in cattle (NB rare)
Most likely hormonal issues; or hypocalcaemia
May relate to fibrosis of the cervix
26
What is associated with incomplete relaxation of vagina and vulva
Dairy heifers
Over fat body condition
Or interruption during parturition
27
What direction does uterine torsion more commonly go in
Anticlockwise
Usually 90-180 degrees
28
When can't we correct uterine torsion per vaginum
If anterior to vagina
Or >270 degree torsion
29
What is an episiotomy
Making a cut to increase diameter of vulval opening
Should be done dorso-laterally at 11 or 1 o'clock
30
Options to deal with feto-maternal disproportion
> Supplementing contractions with traction
> Episiotomy to increase vulval opening diameter
> C section
> Fetotomy to reduce volume
31
How soon do we want a calf out within traction being applied
10 mins
32
At what point in posterior delivery must we avoid any delays because calf compromised
Once umbilical cord trapped; i.e after tail head and anus is out
33
What is 'true breech' presentation
Hip flexion; to correct should retropulse then push limb into hock flexion and then straighten this
34
What is the normal position for birth
Dorso-sacral i.e fetal spine upwards towards maternal pelvis
35
What does dorso-pubic position mean
Fetal spine is down towards pelvis i.e upside down fetus
36
What does dorso-iliac position mean
Fetus lying on side
37
How can we use pressing eyeballs in calves to correct faulty position
Triggers a convulsive reflex
38
How many cuts does a complete fetotomy usually require
4-6
39
Difference between a subcut and percutaenous fetotomy
Subcut is within skin; can be used to remove forelimb in anterior presentation; incise skin a little and break down muscle
Percutaneous = making full cuts through body
40
What is the most common reason for fetotomy
HIp lock
41
post-fetotomy management of a cow
Uterine flushing
Oxytocin to aid involution
NSAIDs and antibiotics
Fluids
42
What is prognosis of a c section most related to
Duration dystocia has been left
43
What is the preferred surgical site for cow c section
Left flank standing laparotomy
44
What is a complication with giving xylazine for sedation during c section
Increases the intensity of uterine contractions
+ can reach calf and cause sedation; reduces fetal cardiovascular function
45
What is a side effect of clenbuterol (for myometrial relaxation)
Delays uterine involution
46
Options for cow c section anaesthesia
Line block; over incision site BUT delays healing
Inverted L block; above and to side of of incision - won;t affect healing
Paravertebral block
Can do epidural
47
What limb will we palpate during c section depending on presentation
If anterior; will feel hindlimb
If posterior; will feel forelimb
48
How to repair a uterine incision; abdomen and skin
Continuous layer of inversion sutures for uterus
Continuous sutures for muscle
Non-absorbaby ford-interlocking or horizontal mattress for skin
49
When might we choose a right flank incision for C section
Lots of previous C sections so much scar tissue
L side not accessible
Fetus in right horn
50
When might we choose a ventral/midline incision for C section
If calf dead/emphysematous to avoid fluid spilling into the cow
- Must sedate cow and cast in lateral recumbency
51
MOst common causes of dystocia in EWEs
Most common = fetal maldisposition
Then obstruction of birth canal
MUCH MORE RARE to have it due to disproportion
52
Considerations when approaching dystocia in the ewe vs cow
Uterus more friable so take care
+ More risk of infection so must be more hygienic
Tissue breaks down easier so easier to do a subcut fetotomy compared with cow
53
What position do we normally do a c section in a sheep
Lateral recumbency
54
Treating acidosis in neonatal calves
Inject 50ml of sodium bicarbonate
55
Incidence/consequences of retained fetal membranes in cows vs sheep
More common in cows
BUT worse consequences in sheep
56
How common is RFM incidence in cows
8-12%
57
Risk factors for RFM
NB: management factors involved because separation process starts weeks pre-partum
* Age, dystocia, multiple births, inductino
* infection-related abortion
* Deficiencies in cit A, E, selenium, Ca2+, Cu2+, iodine
* High body condition; fatty liver syndrome
* Hormones; lack of PGF2a, low progesterone, hgih oestradiol
58
What treatments can help with RFM
Avoid manual removal esp on septicaemic animals
Antibiotics; only if systemically ill + only parenteral
Hormones: PGF2a if low in this; oxytocin if in first 24hours post-partum
59
Contributing factors to uterine prolapse
Poor uterine tone
Oversized fetus
Prolonged dystosia
Increased intra-abdominal pressure
High oestrogens in diet
Too high BCS
60
What is the New Zealand method for correcting uterine prolapse
Pull back legs all the way back; then sit between legs and correct
61
In what breeds do we sometimes see congenital ovarian hypoplasia
Swedish Highlands
White ayrshire
62
At what age should cows be cycling
By 12 months old; but may be later if underfed
63
What is white heifer disease
form of segmental aplasia due to sex linked recessive disease
- Get occlusion of the genital tract due to incomplete canalisation or septae presence
64
What are freemartins
Females which have been exposed to testosterone in utero due to male twin (NB: male may have died in utero)
- Get absence of normal repro tract, masculinisation of calves e.g prominent clitoris; short vagina; testes present
> Diagnose definitively via blood test
90% of females with male twin affected
65
What are ovario-bursal adhesions
Fibrous tissue that sticks ovaries to ovarian bursa; impacts ovulation
Usually on R side
66
What is hydrosalpinx
Where there is blockage of ovarian tubes which then fill with secretion; tubes will become palpable
67
What is the most common type of ovarian tumour
Granulosa cell tumour; usually oes producing so get nymphomaniac behaviour
68
effect of fibropapillomas in uterus and cervix on fertility etc
No effect on fertility
BUT can interfere with parturition
69
Which type of cows are often 3 wave rather than 2 wave
Beef cows
Dairy heifers
70
How does maternal recognition of pregnancy in the cow work
Fetal trophoblasts secrete IFN-tau from day 14; this blocks oxytocin receptors on the uterus so they don't respond to oxytocin
--> Don't release of prostaglandins
71
What is anovulatory anoestrus
No ovulation
see small flattened ovaries, no CLs, no uterine tone, little vaginal mucus
Follicles are <8mm
72
What is the minimum size follicle for ovulation in a cow
8mm
73
What can we tell about where the problem is in follicular development based on follicle size
If all <4mm: likely from emergence to selection i.e FSH issue (severe malnutrition)
If 4-8mm: issue from selection to dominance; GnRH issue
If some >8mm: issue is with ovulation i.e LH surge
74
In anovulatory anoestrus; what size follicles can we use GnRH on to cause ovulation/leutinsation or atresia
>4mm
If less than this = a DEEPER ANOESTRUS so this is less likely to work
75
What do we use to treat deep anoestrus in cattle
Progesterone vaginal implant; should get resumption or normal cyclical activity once removed
76
Why do we use eCG in treating anoestrus in cattle
Has FSH-like activity
77
Difference between follicular and luteal cysts
Follicular cysts are thin walled
Luteal cysts are thicker walled (>2mm) with luteal tissue
78
Why might early CLs be misdiagnosed as luteal cysts
They have a fluid centre at the start (trapped during formation) BUT this will be gone by the time of normal PD diagnosis
79
Why do we get cystic ovarian disease
Lack of LH surge so follicles continue to grow without ovulating
80
Approach to treating follicular vs luteal cysts
Follicular: can give GnRH to cause LH surge; hCG/LH; progesterone to re-establish hypothalamic action
Luteal cysts: progesterone; PGF2alpha for luteolysis
81
What are possible causes of lack of oestrus but CL present
MOST LIKELY = JUST MISSING OESTRUS SIGNS
- Persistent CLs
- Subclinical endometriosis; can cause failure of uterus to release PGF2alpha
To treat can use PGF2alpha to get rid of CL
82
How could we deal with delayed ovulation causing inappropriate insemination timing
Give GnRH at service to induce ovulation
83
What is the main cause of repeat breeders
Ovum not reaching sperm e.g due to ovarian bursal adhesions
84
How could we deal with poor quality CLs in high yielding dairy cows
Give GnRH at service and/or 11 days later to cause development and leutinisation of other follicles
85
What can cause short cycles
Cystic ovarian disease
86
At what % mature weight/age should we serve heifers
60% mature weight
Usually about 15 months old
87
How can negative energy balance affect fertility
Reduced LH pulse freq
Reduce insulin
Reduced oestradiol from follicles
Deleterious effects of BHBs and NEFAs
88
Why should we avoid excess rumen degradable protein in relation to fertility
Ammonia and urea have negative effects on oocytes and embryos
+ can exacerbate -ve energy balance because uses energy to make this safe
89
timing of ovulation in relation to oestrus
Ovulation 12-18 hours after the end of oestrus
- Follow AM/PM rule
90
Which opportunistic bacteria causes non-specific infections of genital tract
Staph, strep, trueperella, E coli, other anaeroes (fusobacterium, clostridia, bacteroides)
91
Under which hormone dominance is the immune system weaker
Progesterone
(to avoid new conceptus being seen as foreign)
92
What is metritis
ACute-peracute inflammation of endometrium/myometrium after calving
> may be subclinical or be more peracute with toxaemia
93
Why might we avoid doing uterine irrigation in acute metritis cases
Uterus is friable so risk of rupture
94
how do we grade endometritis
Baseon on what the secretion looks like
From 0-2; 0 = normal, 2= 50% pus/mucus
95
How do we treat endometritis
With inter-uterine antibiotic e.g cephalosporin via catheter (no milk withdrawal)
+ may do hormonal treatments:
- PGF2alpha: for luteolysis of persistent CL
- GnRH for early resumption of cyclicity
96
Why do we get pyometra and how do we treat
Because cervix remains closed; usually due to CL or luteal cyst
- So can use prostaglandin to lyse the CL
97
Which bacteria cause specific infections of genital tract; i.e without predisposing causes
Brucellosis, leptospirosis, salmonella, bacillus, listeria
98
Characteristics of brucellosis abortion
From 5 months +
= notifiable (causes undulant fever in man)
Infection is via ingestion of organism from recent abortion
99
What is the most common (ly diagnosed) cause of abortion in cattle
Neospora caninum
100
Characteristics of neospora abortion
4-6 months
Autolysed fetus
101
What is the most important route of transmission of neospora caninum in cattle
Vertical transmission
102
Diagnosing neospora as cause of abortion in cattle
+ve serology result NOT diagnostic
BUT -ve result does rule it out
103
Consequences of leptospira infection or shedding in pregnancy
Early embryonic death (infertility)
Abortion; late gestation
premate/weak calves
See sudden milk drop in mother
- NB: usually no symptoms if not pregnant
104
Which organ might leptospira isolate into and start shedding from
Kidneys
105
Which species of campylobacter causes abortion in cattle
C fetus subspecies fetus; more so abortion
C fetus subspecies venerealis; more so infertility
106
How does campylobacter impact fertility
= venereally transmitted disease where bull is carrier
Embryonic death and infertility; but can also get later abortion
107
Endemic campylobacter situation
Just subfertility because cow gets immunity
- Newly introduced animals become the ones to succumb
108
How can we diagnose a campylobacter abortion
Getting typical organisms from the stomach of fetus
109
Which strain of salmonella is most responsible for abortions
S Dublin
- May have accompanying dysentery OR no clinical signs
110
Which bacillus species causes abortion and at what stage
B licheniformis
Usually late stage 5-7 months
Source = poor silage
111
Characteristics of a listeria abortion
From poorly fermented silage
Fetus AUTOLYSED
112
What does serology for BVD tell us about
EXPOSURE only; but good for herd monitoring
113
BHV1 impacts on reproduction
Abortion rare
Can cause infertility via embryonic death
infectious pustular vulvovaginitis; must stop natural service
114
how is Schmallenberg virus spread
Via culicoides midges
+ transplacentally from viraemic dam to fetus
115
Characteristics and causative agents of mycotic abortions
LATE TERM (7-8 months)
e.g Aspergillus, absidia, rhizpus, mucor
Diagnosis via fungal hyphae in fetal stomach or placent
116
Definition of an abortion in cattle
Expulsion of fetus from 150-270 days gestation
117
Why must we report all bovine abortions to DEFRA
Brucellosis eradication legislation
118
What samples should we send for investigationof abortion
IDeally whole fetus + fetal membranes
119
Is it easier to get heifers or cows pregnant
Heifers; because not also lactating + don't have age-related issues
120
How long after parturition do farmers get dairy cow pregnant (not aiming for 365 day interval)
~ 6 weeks
121
At what point should cows have full uterine involtuion after birth
21 days
122
By which day post-partum should cows have had first oestrus
45 days; this is 'voluntary wait period' for farmers
123
What is calving index and how good is it as a measure of herd fertility
Interval between services; target is 365 days BUT takes a long time and is biased towards successful cows (i.e those not culled)
124
What does 24 days submission rate mean
% cows served within 24 day period of the START of the breeding period (after voluntary 45 day wait period)
125
What should the inter-service interval be
18-24 days; this is the normal length of an oestrus cycle
- IF longer means there was a pregnancy and early embryonic death
- If shorter cow is 'short-cycling'; may be cystic
126
What progesterone levels do we expect in a cow in oestrus
Very low
127
What body condition do we want cows at service, calving and mid-lactation
Service = 2-2.5
Calving = 3-3.5
Mid-lactatino = 2.5-3
128
Metabolic profiles of cows; what can we use to monitor different things
BHB = for -ve energy balance
NEFA = for fat mobilisation
Urea = for daily protein intake
Albumin = for long term protein status
Globulins = for inflammation
129
What does low protein in milk yield or low overall yield suggest about diet
Energy deficit
130
What does low milk fat suggest about diet
Deficient in fibre
131
(no detail) options for synchronising cows
Prostaglandins
Progesterone; implant then remova;
132
How can prostaglandins be used to synchronise cows
Causes luteolysis and return to oestrus in 2-5 fays
> Brings lots of cows into heat at same time so will mount each other etc for detection
BUT won't all ovulate at same time so not good for fixed time AI
133
How can we use progesterone to synchronise cows
Leave impant in for 12 days; then when removing it mimics CL regression SO get oestrus in 2 days
(if leaving P in for less time then will need to use a luteolytic upon removal)
134
How can GnRH be useful in issues with ovulation etc
As a luteotrophin or to induce ovulation
> If delayed ovulation an issue, inject at service for ovulation at predicted time
> If luteal insufficiency an issue, inject at 11 days post service to stimulate the development of accessory CLs
135
How can gonadotrophins be used in cycle manipulation and which ones
hCG has more LH-like activity; to treat follicular cysts or induce ovulation
eCG has more FSH-like activity; to induce ovulation (e.g in instances where progesterone has been used to advance the breeding season)
136
5 main categories of causes of infertility in the male
1) Deficient libido
2) INability to mount
3) INability to achieve intromission
4) Inability to fertility
5) Venereal disease transmission
137
What venereal disease are we worred about bulls passing to cows
Campylobacter fetus subspecies venerealis
138
What age is puberty usually in bulls
9-10 months
139
How might we treat bulls with deficient libido
Hormone therapy e.g hCG every 3 weeks for LH like activity (LH supports Leydig cells to make testosterone)
140
How are LH and FSH involved in male fertility
LH: supports leydig cells to make testosterone
FSH: supports sertoli cells to do spermatogensis
141
What penile neoplasia is common
Warts caused by papilloma viruses
142
What is phimosis
Inability to extrude penis through prepuce
143
What is paraphimosis
Inability to withdraw penis back into prepuce
144
What is a persistent frenulum in bulls
An adhesion from tip of penis to shaft; should have broken down at puberty
- (can be result of early castration)
Simple to correct
145
What ligament insuffiency causes spiral deviation of the penis
Dorsal apical ligament (holds penis straight)
- Can fix this ligament to the tunica albuginea to fix
146
Primary, secondary and tertiary sperm defects
Primary = at time of production
secondary = following exposure to infection or noxious agents in transit
Tertiary = during processing for AI e.g bent tails = cold shock
147
Difference between conpensable and non-compensable sperm detects
Compensable: can still get fertilisation by using different AI technique to reach eggs e.g bent tails
Non-compensable; e.g acrosome defects; won't get fertilisation
148
What infections cause orchiditis
B abortus, T pyogenes, M bovis + some non-specific opportunists
149
What causes testicular degeneration
Toxic damage
Viral infection e.g BHV-1
Physical damage
Autoimmunity
Deviation in normal temp
Gonadotrophin insufficiency
-> See previous good fertility then decrease
150
What scrotal circumference should a bull have
>34cm
151
Caution with interpreting electro-ejaculation sample
Not true ejaculate
More watery; but good for looking at sperm morphology
152
What sperm density do we expect in ruminants
1,000 million/ml
153
What are the cut offs for sperm morphology
>70% should be normal
with <20% of any single abnormality
+ 75% should be live
154
