equine 2 Flashcards
post-breeding endometritis: inflammation, semen, bacteria, and fluid should be removed within _____ of breeding
48 hours
if post-breeding endometritis is unresolved after ____, the mare is susceptible to _____.
48 hours
persistent breeding induced endometritis (PBIE)
Persistent breeding induced endometritis (PBIE) leads to —?
infectious endometritis and/or fibrosis if not treated due to the intense inflammation
what is the most common cause of infertility/subfertility in the mare?
PBIE
how do you diagnose endometritis in the field?
US
accumulation of > 2cm of uterine fluid
- during estrus or within 36 hours of being bred
what is going on in this US of a mare?
endometritis
how and when is PBIE treated?
- tx on presumptive dx (US), particularly if mare conceived
- w/ uterine lavage (Ringer’s) prior to and/or post breeding; oxytocin (wait 6h post AI), antiinflammatories, ± PGF2alpha
- repeat 6-12-24 hours if needed
- if no pregnancy occurs, cytology and culture
tell me the 2 broad risk factors for PBIE
- delayed mechanical clearance = prevents adequate lymphatic drainage post-ovulation and cervical closure
- uterine contractility dysfunction
tell me some things that result in delayed mechanical clearance in the mare, which is a risk factor for PBIE
- perineal conformation
- vaginal stretching
- cervical dysfunction
- pendulous uterus
- scar tissue in the end/myometrium
uterine contractility dysfunction results from _____, which is a risk factor for PBIE
improper response to oxytocin or prostaglandin
which mares receive prophylactic treatment for PBIE?
- mares who have failed to conceive
- mares who are older than 10 years
what is the prophylactic treatment for PBIE?
- uterine lavage post-breeding
- oxytocin to improve contractility
- PGF2 alpha
- antibiotics should only be used if confirmed bacterial culture
how do you manage PBIE?
- Caslick’s
- choice of breeding method
- investigate semen handling
what is the easiest and most efficient way to prevent bacterial contamination and improve conception rates?
Caslick’s vulvoplasty
biofilm formation is often associated with _____ bacteria.
gram -
- e coli, pseudomonas, klebsiella (some strep strains)
why are biofilms important to know about?
- bacteria are distinct from free-floating counterparts –> evade host immune system, not susceptible to routine tx
- difficult to dx and tx
- repeat infection rate is high
you should always suspect ____ with gram - bacteria
biofilm
how do you tx biofilm?
- antibiotics combined with biofilm disrupters (tris EDTA or DMSO) (common ABs)
fungal endometritis is often associated with ?
physical issues of the repro tract (pneumovagina, urovagina, cervical issues, etc)
overuse of ABs! – do not routinely use ABs with PBIE
what is the normal gestation length in the mare?
335-342 days
tell me the timeline and what happens during early pregnancy in the mare
day 0: early fertilization
day 2: 2-cell stage
day 4-5: morula
day 5-6: blastocyst
day 6.5: enter into uterus, PGF2alpha
day 8: capsule
day 10-16: mobility, PGF2alpha, can give NSAIDs
day 16: fixation
day 21: loss of the capsule
day 24: heartbeat
what is the function of the capsule during early pregnancy?
- required for development
- anti-adhesive property due to high content in sialic acid residues
- mechanical stability, able to withstand uterine contractions
conceptus is mobile from _____ days. how is it mobile?
10-16 days
conceptus secretes PGF2alpha –> uterine contractions –> conceptus gets propelled within the uterine lumen
I asked AI to generate art for me, showing an egg on a roller coaster having fun, and this is what it gave me
why is the egg mobile during days 10-16?
mobility is important for material recognition for pregnancy
this is poorly understood in the mare
recognition prevents endometrium from producing further PGF2 alpha, allowing CL to remain
what allows for fixation of the conceptus?
uterine tone + embryo size
tell me how to diagnose early pregnancy in the mare. tell me about which days you can see what.
transrectal US
day 10: embryonic vesicle (yolk sac)
day 14: easily detectable (~15mm)
day 21: embryonic vesicle looses its perfectly round shape
day 24: embryonic heartbeat visible
day 30: embryo seems to ascend within its vesicle
what is this an US of?
day 14 (?) embryo
what is the red arrow pointing to?
day 21 embryo
what is the red arrow pointing to?
day 24 embryo w/ heartbeat
what is the US of? what are the red arrows pointing to?
day 30 embryo ascending within its vesicle
upper arrow: regressing yolk sac
lower arrow: developing allantoic cavity
it is crucial to examine for twin pregnancy on day _____ and no later! why?
day 14
conceptus fixation at day 16 - you can’t pinch off one egg anymore
what are these US’s showing?
twin pregnancy
if you find twins in a mare on day 14, what can you do to manage it?
separate twins as far as possible, crush one embryonic vesicle (feels like a grape)
true or false: past fixation, there is nothing you can do to manage twins in the mare other than abort
false. there are more advanced options for managing twins, and one will sometimes regress in the first trimester
true or false: endometrial cups are found in all mammals
false. unique to horses/equids
endometrial cups form in the ___ horn around day ____ of gestation
gravid
36-38
what do the endometrial cups do?
produce copious amounts of equine chorionic gonadotropin (eCG)
play a role in maternal immune response/tolerance
tell me about how endometrial cups differ in size and hormone production throughout gestation
- mature in size and hormone prod. at day 55-70
- decline in size and hormone conc. from day 80-150
- eCG usually not detected after day 150
what are these?
endometrial cups
eCG has predominantly ___ behaviour, some ___ behaviour.
LH, FSH
eCG and LH do what in the mare during early pregnancy? why does the mare do this?
FSH stimulates development of dominant follicles during early pregnancy, LH & eCG luteinize the dominant follicles forming accessory CLs
to help maintain pregnancy (produce more progesterone)
progesterone drops after a time, and without eCG, pregnancy would terminate because progesterone would continue to drop
CL’s produce progesterone until placenta takes over
when does eCG peak in the mare?
day 55-70
does presence of eCG in mare seem indicate presence of a viable fetus? why or why not?
no not really. if there is embryonic death after day 35, it doesn’t result in regression of endometrial ups and eCG levels remain high despite absence of viable fetus
it means that there is or was a fetus at some point and that endometrial cups are present
why are retained endometrial cups an issue?
breeding season is usually lost and no therapy is possible
the problem is that follicles luteinize before they have a chance to ovulate
the fetoplacental unit assumes prod. of progestogens between days ____
50-70
how do you pre-foal prepare?
- move mare to anticipated foaling location about 1 month prior to foaling –> gets her comfortable, allows immune system to adjust to environmental pathogens
- pre-foaling vax should be given at this time
- large foaling stall
-straw bedding or pasture
why is predicting or inducing parturition in the mare problematic?
fetal lung maturation is only within the last 24-48 hours - and we have no idea when this is
tell me what’s in a foal kit
- tail wrap
- umbilical dip
- enema
- gloves to remove placenta/plastic bag
- scissors
- stethoscope
- thermometer
- basic first aid
- clean towels
- buckets
what are the normal signs of impending parturition?
- mammary development
- mammary secretions
- dropped belly/pendulous abdomen
- elongation of the vulva
- softening of the tail head
- behaviour changes
how do we use mammary development to predict parturition?
- mammary development begins 30 days before parturition
- waxing 24-48 hours before foaling
tell me how we use mammary secretions to predict parturition
- 24-48 hrs prior to foaling: Ca >10 mmol/l or >200 ppm
- 3-5 days before birth, Na to K ratio inverts (K will be higher than Na)
Na ≤ 30 mmol/L
K ≥ 35 mmol/L
how many stages in mare parturition?
3
describe stage 1 of mare parturition
- lasts several hours to several days
- mare is restless, crampy, patchy sweating, there is varying levels of uterine activity
- fetus begins to engage with cervic and pelvic canal
- fetus rotates from dorsal pubic to dorsal sacral position - may be facilitated by rolling behaviour
- chorioallantois ruptures at end of stage 1
describe stage 2 of mare parturition
- active pushing that lasts for 15-20 mins
- ends with expulsion of fetus
- foal should be anterior, longitudinal, and dorsal sacral
- should see amnion at vulvar lips if chorioallantois has ruptured appropriately
what is red bag?
during stage 2 of parturition, you may see red tissue at vulvar lips. this is premature placental separation. when this happens, the foal is no longer getting O2 from the placenta and the foal must be delivered as soon as possible !
describe stage 3 mare parturition
- up to 3 hours
- passage of placental membranes
- rapid involution of uterus begins
induction of parturition is reserved for..?
high risk foals due to risk of premature or weak foals
mare is literally going to die before parturition
how do we induce parturition in the mare? which is the agent of choice?
- glucocorticoids (limited efficacy)
- prostaglandins - elicits potent myometrial contractions, but neonatal adaption complications and fx ribs maybe
- oxytocin
true or false: you should use a high dose oxytocin to induce parturition I the mare.
false! USE A LOW DOSE!
true or false: like cattle, retained fetal membranes aren’t a big deal in horses
false. they are a serious condition!
fetal membranes usually pass within ____ in the mare.
3 hours
retained fetal membranes can be?
- delayed repulsion (12 hours)
- partial retention
- complete retention
partial retention of the fetal membranes in horses usually involves what part of the placenta?
tip of the non-gravid horn
how do you treat retained fetal membranes?
- ecbolic agent (oxytocin)
- antimicrobials (SMZ, gentamicin + penicillin)
- NSAID (flunixin meglumine)
- uterine lavage (sterile saline sol, 34g salt per 1 gallon water aka 25 ml salt)
- burn’s technique (chorioallantois distended with dilute poe-iodine or saline for 15-30 mins)
sooner rather than later!
true or false: uterine tears are an infrequent but serious postpartum complication
true
after dystocia (1/3) or for unknown reasons (2/3)
what are the C/S of uterine tear?
- mild colic
- often occur in the tip of a horn = usually not palpable
how do you dx uterine tears?
history with abdominocentesis (signs of peritonitis)
how do you tx uterine tear?
sx
prognosis is good if dx early
uterine hemorrhage occurs most commonly in _____ (party) mares _____ (age). when can is occur?
multiparous
>15 years
may occur during pregnancy, at foaling, or days after foaling
what vessel is involved in uterine hemorrhage?
middle uterine artery
what are the C/S of uterine hemorrhage?
- acute onset mild colic to severe pain
- sweating in combo with cold extremities (i.e classic signs of hemorrhage)
how do you dx uterine hemorrhage?
- hx
- transabdominal US & abdominocentesis if bleeding into abdominal cavity
- palpation if bleeding occurs into the broad ligament or uterine wall
if the mare has uterine hemorrhage, should you breed her again?
nope
what are the risk factors for retained fetal membranes?
- placentitis
- serum Ca imbalance
- poor myometrial contractions (low Ca, exhaustion)
- age of mare
- abortion
- dystocia
- short/long gestation length
- breed predisposition (Friesians!)
- previous hx
what are the causes of uterine hemorrhage?
- hemorrhage into broad ligament of uterus
- hemorrhage into abdomen
