Equine Reproduction Flashcards
(125 cards)
1
Q
when do fillies and colts become mares and stallions?
A
filly <2 years female
colt <4 years entire male
2
Q
what is an embryo?
A
conceptus under 50 days old
3
Q
what is a foetus?
A
conceptus over 50 days old
4
Q
what type of oestrus do mares have?
A
seasonally polyoestrus
5
Q
when doe mares naturally cycle?
A
spring to autumn
6
Q
what is mare cycle simulated and stopped by?
A
brought on by increasing day length and cease as days shorten
7
Q
how long is a mares oestrus cycle?
A
21 days
8
Q
what hormone causes the regression of the corpus luteum?
A
prostaglandin f2 alpha
9
Q
why do mares need to foal in early spring/summer?
A
need foal to grow before winter
UK weather is unpredictable
10
Q
when should mares be covered?
A
during the month after the month you wish them to foal in next year
11
Q
why is it advantageous for thoroughbreds to be born early in the year?
A
when racing they race against all horses born in the same year as them
if born later they are less mature and less strong
12
Q
when do breeders aim for their thoroughbred mares to foal?
A
after 1st January (to avoid being very young in their year) but close to
13
Q
when are thoroughbred mares covered from?
A
valantines day
14
Q
how are thoroughbred mares manipulated to come into season early?
A
lights and drugs
15
Q
how can ovulation be induced in mares when they are sent to stud after their foal is born?
A
use of prostaglandin which causes corpus luteum regression and cycle within 2-3 days
16
Q
what are the pre-breeding checks performed on a mare before or when she arrives at stud?
A
general health (clinical exam)
presence of strangles
reproductive health
17
Q
how is the reproductive health of the mare checked before or on arrival at stud?
A
clitoral fossa and sinus swabs
18
Q
what swabs should be used for clitoral fossa and sinus swabs?
A
ENT as smaller
19
Q
what must clitoral fossa and sinus swabs be transported to the lab in?
A
Amies charcoal - prevents bacterial growth
20
Q
what are clitoral swabs of mares checking for?
A
taylorella equigenitalis
pseudomonas aeruginosa
kiebsiella
21
Q
what is caused by taylorella equigenitalis?
A
contagious equine metritis
22
Q
what is significant about contagious equine metritis?
A
notifiable
23
Q
how must clitoral fossa and sinus samples be sent to the lab?
A
name, date, time and site of sample
ensure swabs in date and sample is sent quickly
24
Q
what are the pre-breeding checks performed at stud?
A
endometrial swabs for cytology and culture and sensitivity
ultrasound scan of ovaries
ultrasound scan of uterus
25
what are you looking for on a pr-breeding scan of the ovaries?
follicle developmet
26
what are you looking for on a pre-breeding scan of the uterus?
free fluid
| cysts
27
what is teasing?
testing whether a mare is in season (behavioral oestrus) by seeing if she is receptive to a male horse at her head or rear
28
what stallion is normally used as a teaser stallion?
pony stallion
often low value and cheap to keep
sometimes use the stud stallion
29
what are the oestrus behaviours in mares?
```
lifts tail
winks vulva
squirts urine
wide legged stance
acceptance of male presence
doesn't kick out at stallion
tolerates stallion attention
```
30
what is the response to oestrus behaviour seen by stallions?
```
phlemen posture (vomeronasal organ)
sniffs, nuzzles then bites hindlimbs and perinuem
drops penis
penile erection
will cover mare if allowed
```
31
when can the best time to cover a mare be determined?
ultrasound which shows larger follicle, uterine oedema that is beginning to wane and no free fluid in uterus
32
how large should the follicle be pre ovulation?
approx 5cm diameter
33
how should the mare be prepped when viewing her cervix?
clean perineum with warm soapy water - no hibi or iodine
34
how is cervix visualised?
speculum and torch
35
what does the cervix look like during oestrus?
red
engorged
saggy
36
what does the cervix look like in dioestrus?
pale
small
tight
high up off vestibule floor
37
what method of covering must be used to be weatherbys registered?
natural (AI not permissable)
| covering certificate will be issues
38
what may the stallion handler do during covering to ensure ejaculation has occurred?
palpate ventral penis
39
when does in hand covering occur?
once teasing and scanning has determined appropriate time
40
what safety equipment is needed for covering in hand?
human - hat, gloves, boots
mare - wither guard, hind boots, bridle, hobbles, tail bandage
stallion - specific bridle/chain, lunge line, fore feet boots
41
what should be done the day following covering?
tease or ultrasound to see if still in oestrus
42
what will happen if the mare is still in oestrus following covering?
may cover again (ideally every other day of oestrus)
43
what will happen if the mare is not in oestrus following covering?
manage as normal
tease again from 18 days
ultrasound from 12 days to see if pregnant
44
where does unassisted covering occur?
in herd or individual
short term or permanent (e.g. native herds)
free in field and supervised
45
how is unassisted covering managed?
timings determined by horses
less control / human intervention
natural
unsure fo exact dates
46
what are the 3 types of AI semen available?
fresh - local stallion
chilled - stallion in country
frozen - globally
47
how is semen collected for AI?
using a dummy and AV (integral or separate)
| use towel soaked in in season mares urine or have an in season mare nearby to encourage stallion
48
is semen collection often performed using a mare?
no - ethically questionable
need sedation and repeated restraint
dummy much more common
49
what is found in an artificial vagina?
```
filled with warm water
lined
lubricated
insulated
semen collection vessel on end
filter between chamber and semen collection pot
```
50
what temperature should the water in an AV be?
crucial
| 38 degrees but varies between stallions
51
what must not be mixed with semen in an AV?
water - will destroy semen
52
what may be included to preserve semen?
extender - acts as a buffer to stabilise sperm
53
how is timing of AI managed?
based on ultrasound scans when a large follicle is present in the ovary
54
if ovulation is induced how can AI be managed?
fixed time insemination 36-40 hours after injection of HCG
55
what is the typical dose of sperm AI?
100-500 x10^6 progressively motile sperm
56
how is AI performed?
use speculum or hand per vaginum to guide catheter in
place catheter inside uterus through cervix
instill semen
57
where are the 2 main locations semen may be placed in the uterine body?
```
conventional (60 cm catheter)
deep horn (75cm catheter)
```
58
how is the mare managed post covering / AI?
removal of free fluid associated with semen, extender and inflammatory reaction
vulvoplasty / caslicks procedure if needed
monitor with ultrasound
ensure uterus is ready for implantation of uterus within 5 days
59
how is removal of free fluid associated with semen, extender and inflammatory reaction performed in the mare post covering / AI?
lavage with sterile isotonic fluid (Hartmann's)
| induce uterine contractions and encourage movement to hepl remove fluid
60
what is the purpose of a vulvoplasty / caslicks procedure?
prevent air, faecal material from entering vestibule and causing ascending infection
61
when is embryo transfur performed?
on a 7-10 day blastocyst
62
what is complex about embryo transfer?
donor and recipient must be synchronised
requires expertise
expensive
63
how is pregnancy diagnosed?
ultrasound
failure to return to oestrus
blood sample
urine sample
64
when can ultrasound confirm pregnancy in horses?
12 days but care with twins so many wait till 14-16 days
65
when does failure to return to oestrus indicate pregnancy?
at 21 days post covering
66
when can blood samples show pregnancy in mares?
equine corionic gonadotrophin at 60 days
| oestone sulphate from 120 days
67
what is the advantage of oestone sulphate over equine chorionic gonadotrophin in diagnosing pregnancy?
indicator of live foal as it is produced by foetal placental unit
eCG can be raised with pseudopregnancy
68
when can a urine sample indicate pregnancy?
from 120 days - placental oestrogens
69
what are the conception rates in horses?
approx 80%
70
why are twins so often aborted?
when demands of foals exceed placental surface area capacity to provide required nutrients and oxygen
71
how may twins be born?
non - identical
rarely survive - often abort
may be mummified foetus born with live foal
72
what should be done if twins are identified on ultrasound?
one or both should be terminated
73
how is termination of twins performed?
pinching of one at 14-18 days
| prostaglandin to terminate both
74
what is the risk with pinching one twin?
may terminate both
75
when must a twin be terminated?
before endometrial cups sustain pregnancy (day 35) otherwise both must be terminated
76
what should a mare with twins be scanned for following pinching?
check there is a single one remaining
| look if there are uterine cysts
77
how long does pregnancy last for?
~340 days / 11m 11d
78
when is a foal classed as premature?
310-325 days
79
when is a foal non-viable?
earlier than 310 days - abortion
80
what are the signs of imminent foaling?
udder development - waxing up, dripping milk
mares vulva relaxes
increased sweating (foaling alarms)
81
is dystocia common in horses?
no - usually rapid and uncomplicated delivaries
82
what must be done if complications do arise during foaling?
rapid action to save foal and mare
| c-section is possible under GA
83
how long does stage 1 last for in mares?
1-4 hours
84
what occurs during stage 1 of labor?
foal enters pelvic canal
stimulation of dilation of cervix and vagina
progressive uterine contractions of increasing strength run from tip of uterus to cervix to psuh foal and placenta in correct direction
85
what are the signs of stage 1 labour in mares?
```
restless
getting up and down
looking at abdomen
sweating
frequent urination
```
86
what should be done while the mare is in stage 1 labour?
wash perineum
bandage tail
reverse caslicks (epesiotomy)
87
how long does stage 2 of labour last for?
15 to 30 mins max
88
what happens during stage 2 of labour?
allantois ruptures at cervical star releasing fluids
strong contractions from uterus
voluntary contractions from abdomen
amnion becomes visible with foal inside
foal presents 2 forefeet and head
hindlimbs will remain in uterus while mare rests
89
what does the time while the mare rests with the hindlimbs of the foal undelivered do?
gives time for blood to return from the placenta to the foal
90
what happens when the mare stands after the foal is delivered?
umbilicus breaks
91
how long does stage 3 of labor last?
<3 hours
92
what happens during stage 3 of labour?
contractions of uterus from tip to cervix to invert placenta and expel it along with lochia (fluids)
93
what should you do if the placenta has been retained for more than 3 hours?
urgent veterinary advice sought
| can cause endotoxaemia and laminitis
94
how many layers does the equine placenta have?
6
95
what are the 6 layers of the equine placenta?
```
chorionic capillary epithelium
chorionic connective tissue
chorionic epithelium
endometrial epithelium
uterine connective tissue
uterine capillary endothelium
```
96
what layers of the placental are the foetal membranes?
chorionic capillary epithelium
chorionic connective tissue
chorionic epithelium
97
what are the maternal layers of the placenta?
endometrial epithelium
uterine connective tissue
uterine capillary endothelium
98
what type of placenta do mares have?
epitheliochorial
99
what does a non-deciduate placenta mean?
fetal and maternal layers are seperate
100
what is a diffuse placenta?
one with villi spread over virtually all of the placenta apart from endometrial cysts, cervical star or twin to twin contact
101
what must be ensured about the placenta?
is passed in entireity
102
how can you be sure the placenta has all been passed?
collect from stable before traumatised
examine external and internal surface
fill with fluid to see if there are any tears - indication of complete removal
103
where is a placenta likely to be retained?
non-pregnant uterine horn
104
what is the 1, 2, 3 rule of foals?
stands in 1hr
drinks in 2hr
placenta passed in 3hr
105
what is defined as dystocia in mares?
once allantochorion ruptures (water breaking0
no amnion or foal at vulva within 5 mins
no strong contractions within 10 mins
foal makes no progression over a 5 minute period - viewed or palpated
106
what are the options if dystocia occurs?
```
vaginal assisted delivery
controlled vaginal delivery
c-section
embryotomy
euthanasia of mare following crash c-section under GA
```
107
if using vaginal assisted delivery when should referral occur?
if no progress within 5minutes
| if not out in 30 minutes
108
what is the treatment of dystocia determined by?
cost
live foal/dead foal
owner
vet
109
what can happen while a controlled vaginal delivery is taking place within hospital?
mare will be prepped for a c-section in case the vet cannot deliver the foal vaginally
110
what position is best for controlled vaginal delivery in the hospital setting?
GA
| hindlimbs elevated to allow the foal to be manipulated
111
what does the survival of c-section in an emergency depend on?
time of onset of stage 2 and proximity to hospital so speed of delvary
112
what are the survival rates for elective C-section?
90% survival of mare and foal
113
what horses require a passport?
all horses born after 2005
114
what horses must be microchipped?
all horses applying for passport since 2009
115
since 2018 what has been the rule about microchips?
all horses now need a microchip irrespective of time of birth and passport
116
what regulations govern passports?
horse passports regulations 2009
117
what is issued to a horse with it's passport?
unique 15 digits life number
118
what is a passport required for?
travel
selling the horse
slaughtering
119
what section of the passport declares whether a horse is fit for human consumption?
section IX or 2
120
who can issue passports?
```
many passport issuing organisations (PIO)
breed
discipline
colour
may be studbook inclusion
```
121
what are the 2 registers governed by wetherbys?
thoroughbred
| non-thoroughbred
122
when should the application for a passport be made after the horse is born?
december 31st of year born
when foal is 6 months
whichever is later
123
what is required on the passport application form?
```
owner details
microchip number
ID certificate (can include photos)
owner and competant authority
vet stamp
```
124
where are microchips placed in horses?
into nuchal ligament
125
describe how to place a microchip in a horse?
scan neck to ensure no chip present
scan chip to check the number
insert the chip into the nuchal ligament
scan neck to check placement
