Lecture 18: Equine Theriogenology Flashcards
Estrogen induces __, they have __behavior
estrus, heat
Lutenizing hormone is the __induction agent
ovulators
LH is responsible for __maturation, production of __, __ and __
follicular maturation, production of estrogen, ovulation and lutenization
FSH is responsible for
follicular recruitment
progesterone suppresses __behavior
estrus
progesterone suppresses __ and prevents __
LH, ovulation
progesterone is produced by __
CL
what hormone maintains pregnancy
progesterone
GnRH promotes release of __ and __
FSH and LH
GnRH is the __induction agent
ovulatory
PGF2alpha induced __
luteolysis
PGF2alpha released __-__ days after ovulation if no embryo
13-16 days
how long is estrus cycle
4-6 days
what is dominant hormone during estrus
estrogen
what is mare behavior like during estrus
solicitous, squat, urinate, winking, clitoral eversion
What do you feel on palpation during estrus
uterus is very soft with edema, large follicles
How long is diestrus
15-17 days
what is dominant hormone during diestrus
progesterone
what is mare behavior like during diestrus
rejects stallion
what do you feel on palpation during diestrus
uterus is toned
horses are seasonally __, normally breeding season is __-__
polyestrous, April-October
describe the transition out of seasonal anestrus
as day length increases follicles begin to develop but will not ovulate until enough LH is present to trigger ovulation
how can you stimulate estrus out of breeding season
16hrs of light exposure
when is seasonal anestrus
November-march
what do you feel on palpation during anestrus
small ovaries, flaccid uterus
__ and __ indicate they are no longer in seasonal anestrus
ovulation and resultant CL
what is ultrasound findings during estrus
edema and dominant follicle >25mm
ultrasound of uterus describe images A-D
A. Diestrus- no edema
B- some edema
C- good amount edema
D. Optimal edema for in heat
ultrasound uterus identify 1-2
- CL
- Follicles
what can you palpate rectally on mare- repro organs
ovaries- size, presence of follicles
Uterus toned vs edema
Cervix- shape and tone
what can you not palpate rectally for repro organs in mare
ovaries- presence or absence CL
Uterus- early pregnancy
Cervix latency
A __ on the ovary is proof that mare is cycling
CL
what is live cover breeding and when should it be done
natural breeding- one cover one dose
Prior to ovulation
how much sperm in fresh cooled per dose
1 billion
when should you inseminate fresh cooled sperm
prior to ovulation and within 48hrs of collection
how many sperm in frozen samples
250-300 million per dose
when should you inseminate frozen semen
6hrs pre or post ovulation
where do you deposit cooled fresh semen
into cervix
where do you deposit frozen semen
deep horn insemination- pass through cervix to uterine body/horn
what is MOA of deslorelin/ GnRH analog
release of FSH and LH
what is indication for deslorelin
ovulators agent
when do you use deslorelin
administer when follicle >35mm with good edema, 70% of mares ovulate in 48hrs
if you have retained fluid or endometritis post breeding what can you give
oxytocin- myometrial contractions
what is oxytoxcin indicated for post breeding
uterine fluid
when do you give oxytocin post breeding
at least 4hrs after insemination
How long is gestation
342 days
what can you see on ultrasound at 15-16 days gestation
embryo implanted
maternal recognition of pregnancy must occur by __days to prevent luteolysis
14 days
what day can you confirm heartbeat on ultrasound
day 25
what do you feel on rectal palpation 2-4 months gestation
fetus size of orange, basektball
what do you feel on 5-7 months gestation on rectal palpation
may not feel uterus because over brim of pelvis
what should you feel on rectal palpation 8-9 months
All baby
t or f: twinning is not good in horses
true
when should you check for twinning
14 days post breeding
75% of mares spontaneously reduce unilateral twins to singleton by day __
40
mares with twins >__days likely hold on to both
40 days
mares with __twins do not reduce
bilateral twins (one in each horn)
what is goal for terminating twining
manually reduce/crush per rectum one twin without damaging other
when do you want to ideally terminate one of the twins
before 30 days gestation, ideally at 14 days
after terminating one twin what medication should you give
prostaglandins for 7 days
if both twins are lost after endometrial cup formation (36-40 days) the mare does not
return to estrus this breeding season
if twins present before 35 days, __ can be given to abort entire pregnancy so that the mare can return to __
prostaglandin, return to estrus this season
what does PGF2alpha do and what indicated for
luteloysis, abortion
prostaglandin may not be effective if >__ months gestation
4 months
what is Caslicks/vulvuoplasty
suturing part of vulva closed to prevent feces from entering
a vulvoplasty also prevent ___ as a cause of colic in mares on track
pneumouterus
what is the correct position of vulva when evaluating for BSE
upright, not tilted forward- feces track in
what are you looking for when evaluating vestibulovaginal seal
negative pressure present
what stain used for endometrial cytology
diff quick
what do normal endometrial cytologies contain
sheets of columnar epithelial cells with few or no WBC, bacteria, fungi or yeast
in healthy endometrial cytology there should be <__/HPF
1PMN/ neutrophil
which of the following cytology is healthy vs unhealthy endometrium
Left- healthy
Right- unhealthy- lots of neutrophils, bacteria
what is endometrial biopsy scoring used for
predict likelihood of carrying foal to term, not conception rate
what is grade 1 endometrial biopsy score
80% or better carrying to term, minimal inflammation or fibrous, healthy glands and lymphatics
what is grade IIa on endometrial biopsy score
50-80% carrying to term, superficial inflammation, early fibrotic changes, cystic dilation
what is grade IIb endometrial biopsy scoring
10-50% carrying to term, more widespread or chronic inflammation, fibrotic
what is grade III endometrial biopsy scoring
<10% carrying to term, sever inflammatory or fibrotic changes, inspissated glands or marked cystic dilation
what are the 3 barriers to uterine infection/ endometritis
vulva, vestibulovaginal fold, cervix
what are the signs of endometritis
fluid retention, failure to conceive, vulvar discharge
what are the 2 main causes of endometritis
- Post breeding inflammatory response (sterile)
- Chronic infection (not sterile)
post breeding endometritis is inflammatory issue with failure to __
clear fluid
which ultrasound images more likely to be indicative of endometritis
C and D- too much fluid
what should you do for suspected endometritis post breeding
- oxytocin >4hrs post breeding
- House near mare- teasing causing myometrial contractions
- Exercise
- Uterine lavage >4hrs post breeding
- +/- antibiotics
what should you do first for suspected chronic endometritis
culture and cytology, if negative consider small uterine lavage
what drugs can you give for chronic endometritis
oxytocin, prostaglandins
What are most common bacterial causes of chronic endometritis and what is tx
- Strep zoo
- E. Coli
- P. Aeruginosa
- Kleb. Pneumonia
Tx: gentamicin or amikacin, potassium penicillin
what are common fungal causes of chronic endometritis and what is tx
- Candida spp
- Aspergillus
- Mucor spp
Tx: fluconazole
Endometrial cysts that are <__ in number and <__-__cm that are not grouped at the base of horns can usually be left alone
5, 2-3cm
what are the negative effects of endometrial cysts
- Interfere with fluid clearance and maternal recognition
- Reduce placental contact with endometrium
- Complicate dx of pregnancy/twinning
Endometrial cysts can be removed with __ or __
laser ablation or electrocautery
horse uterus what wrong
endometrial cysts
what is reproductive senescence/ mareopause characterized by
lengthening of follicular phase, irregular ovulations and eventually persistent anestrus
how do you do embryo transfer
- Breed mare
- Day 5-8 flush donor to remove embryo and place into recipient mare
the donor and recipient mare for embryo transfer must be __
cycling in sync
What is trans vaginal aspiration of follicle
immature follicles aspirated via ultrasound and needle and allowed to mature in vitro
what does progestogens do and what is indication
suppress estrus, disrupt heat cycle
what does oxytocin do and what is indication
down regulation of estrus, disrupt heat cycles
what is the safe ovariectomy procedure
laparotomy»_space;colpotomy
t or f: uterine marbles work to suppress estrus
true
what is average age of puberty in colt
14 months (10-24)
t or f: testes should be fully descended at birth
true
what horses have higher risk for cryptochorchid
percherons and quarter horses
where are right and left testicles likely to be located if unilateral cryptorchid
right- inguinal
Left- abdominal
where are testes likely located if bilateral cryptorchid
abdominal
how do you dx cryptorchidism in horse >3-4yrs/ mature stallion
estrone sulfate- produced by mature testes
what test do you use to dx cryptorchidism in horse <14-24 months
AMH
what are collection methods utilizing artificial vagina
- Dummy/phantom
- Off a mare
- Ground collection
- Chemical collection- impiramine, xylazine
fertile stallions are expected to have __% or better progressive motility
60%
after collecting semen immediately dilute with __ to maximize longevity
semen extender
total sperm per evacuate should be __
4-12 billion
A second collection of semen should happen __hr after first
1hr
second collection of some should have at least __% of first collection
50%
minimum numbers for satisfactory is __morphologically normal, multiple sperm in second sample
1 billion
what do you collect post mortem from stallion if want to breed from them
remove testes, epididymal sperm and as much as ductus deferens
