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202 Cards in this Set

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as the days grow longer, what happens to estrus? what happens to the luteal phase?
estrus gets shorter
luteal phase doesn't change
which phases of the cycle does a horse have?
estrus (follicular phase) and diestrus (luteal phase)
when does estrus get shorter?
how long does DE last and when does a mare stop showing estrus behavior?
14-15 days
-when P4 > 1-2ng/mL
when does the mare ovulate?
the day before the end of estrus
how many follicular waves does the mare usually have? what happens if they have more?
-if they have 2, sometimes the dominant follicle from the first wave will ovulate during DE
what is the average incidence of double ovulation?
-what breeds have the highest incidence?
-thoroughbreds, warmbloods, draft horses
when does LH rise and peak?
continues to rise after ovulation and peaks later
size of horse ovulatory follicles?
large, 30-70mm in diameter
the luteal phase begins with what?
the formation of the corpus hemorrhagicum
what does the CL secrete and what does it do?
secretes P4 which generally inhibits receptive behavior int he mare independent of follicular activity and size
how does PGF reach the ovaries?
it enters the venous drainage and the general circulation and reaches the ovaries by systemic route
after PGF2a is released, how long does it take for P4 to drop below 1ng/mL? what does this cause?
up to 40 hrs
-LH secretion is unblocked and behavioral signs of estrus are seen
what can cause failure of normal luteolysis (deviations in the length of DE)?
-pregnancy recognition
-acute endometritis (shortens DE)
-manipulation of uterine lumen causes luteolysis
-persistent luteal fn (prolonged DE)
how does the change in day length influence the reproductive cycle in horses?
changes in day length --> retina --> optic nerve --> pineal gland (controls melatonin secretion, which is thought to control seasonality through GnRH in the hypothalamus)
-decr day length --> incr melatonin --> inhibits GnRH (*melatonin is "dark" so as it gets darker out, more melatonin is released)
-incr day length --> decr melatonin --> incr GnRH
why are horses referred to as "long day breeders?"
they like to breed when the days are longer
the horse is a ___ breeder? likes to breed when?
explain the four seasons thru horse cycles
1. peak fertility - surrounds summer solstice
2. transition - around autumnal equinox
3. anestrus - around winter solstice (85% of mares in N hemisphere experience winter anestrus, though some are passive to stallion and may permit mounting)
4. transition - surrounds vernal equinox
seasonally, what regulates reproductive activity?
what happens in the spring transition?
-erratic signs of estrus behavior, sometimes prolonged estrus
-follicles growing and regressing (difficult to predict ov)
-breeding would require inseminations every other day for many weeks
best way to adjust breeding/cycling times
-how long until this takes effect?
-on which animals can this be used?
elongating photoperiod - add light either at end of day or split between beginning and end of day
-may require 8-10 weeks
-mares, pregnant mares ( to stop them from going into anestrus), stallions (may advance seasonal incr in sperm prod'n though they never stop producing)
what is a maiden mare?
-good age for fertility
mare that has never been bred or never conceived
-young usually have excellent fertility
problem w/old maiden mares
mares w/repeated pregnancies seem to develop endometrial changes (that interfere w/maintaining pregnancy) slower than aging maiden mares
what is a foaling mare?
-what can delay its return to normal fertility?
mare that foaled during the current breeding season
-dystocia or postpartum conditions
what is a barren mare?
-possible reasons?
a mare bred that previous season that did not foal
--breeding management
--previous foal born too late
--fault of stallion
--pathological condition
name the different categories of % chance of pregnancy and term foal (4)
Category I: normal, > 80% chance
Category IIA: abnormal, 50-80% chance (inflamm = treatable)
Category IIB: abnormal, 10-50% chance (periglandular fibrosis and/or lymphatic lacunae -- suggests ongoing future difficulty w/carrying foal to term)
Category C: abnormal - less than 10% chance (little normal glandular tissue remaining)
two drugs that are used to try and bring a mare into ovulation during late transition period
Deslorelin - requires multiple txs
GnRH - attempts to bring anestrus mares into heat but many injections needed
if trying to advance normal cycling period, when do we want it to begin?
what seems to be the best way to use P4, altrenogest, or progesterone and estrogen txs to advance cycling and ovulation during late transition?
use these in combination with lighting
what can be used to try and advance cycling and ovulation during late transition?
P4, altrenogest, or P&E txs
during late transition, how long after it's given does hCG cause ovulation
~48 hrs (though sometimes won't ovulate or will ovulate then go back into anestrus)
if trying to induce ovulation w/hCG, how big should the follicle be and when does it occur?
-36-48 hrs after injection (IM or IV - not approved)
two brand names for deslorelin
Ovuplant or Biorelease Deslorelin inj
what is ovuplant?
-what is it used for?
---how to prevent problems
a sustained release implant (pellet) of deslorelin
-inducing ovulation
--mares failing to get pregnant may have extended interovulatory intervals
---removal of implant after TWO DAYS or after ovulation prevents this (implant placed in vulvar mucosa so it can be located)
which is better, ovuplant or hCG, and why?
ovuplant bc it doesn't activate antibody formation like hCG does
when does ovuplant take affect?
--how can it be exacerbated?
41-48 hrs after ovulation
--if given PGF2a in DE
difference between ovuplant and biorelease deslorelin injection
no need to take out biorelease bc it's not an implant
-biorelease has never been approved so need a Rx for each patient
when does PGF2a work?
causes luteolysis in CL that is at least 6 days postovulation
when is it basically too late to give PGF2a when trying to short-cycle a mare?
injection more than 9 days post ovulation does not significantly shorten interovulatory interval
how do you use PGF2a to synchronize mares
2 injections, 14 days apart - not perfect but most mares will ovulate 2-10 days after 2nd injection
what is one of the main determining factors of when a mare will come into heat after given PGF2a? explain
follicular size
-the smaller the size, the more days to estrus
-the larger the size, the less days to estrus
what is Regumate and what is it used for?
a progesterone (altrenogest, oral)
-synchronization of estrus
how is progesterone or Regumate (Altrenogest) used to synchronize estrus?
--when does estrus and ovulation occur?
-give 14-15 days
--estrus 4-7 days after stopping treatment
--ovulation 7-12 days after last treatment
what can progesterone and estradiol combination be used for?
to advance cycling and synchronization
What is a portal system?

What are the (3) major portal systems?
Portal systems don't follow a normal vascular parallel arrangement. The vascular arrangement is in series such that blood from the capillaries of one organ is transported to the capillaries of another organ by a connecting vein or veins.

1) Liver - direct arterial supply from hepatic artery but ~70% of supply comes from hepatic portal vein (from gut & spleen - adv. being digestive products processed further in liver)
2) Kidney - Afferent arterioles supply glomeruli and efferent take it away which supply kidney tubules
3) Hypothalamus to pituitary gland w/ functions to transport hypothalamic hormones to pituitary
w/foal heat, when are pregnancy rates higher?
-in mares that ovulate after 10 days postpartum
-in mares w/little or no fluid present in uterus
gestation length
11 months
when does foal heat occur?
around 10 days post-foaling
1 problem with foal heat
some mares to not express estrus, possibly due to distraction of the foal
what can help with ovulation during foal heat?
-how long after does ovulation occur?
-when should you breed?
treatments w/Deslorelin (short acting)
-ov w/i 48hrs
-normal pregnancy rates when breeding occurs on day of tx
what does PGF2a do in a mare?
-induced abortion (if given BEFORE 35 days)
-bring into heat
when must PGF2a be given to induce abortion
before 35 days
what is used to delay foal heat beyond the normal 10 days post-partum?
P4 and estrogen
what is Deslorelin?
synthetic GnRH
Foaling before 300 days is considered...
a premature (nonviable) foal is born before ___ days?
normal gestation length in the mare
335-342 days
long gestation is when a foal is born ...
>360 days
most long gestation lengths result in what?
normal foalings
in which season is gestation length usually longer?
winter and spring
what influences gestation length?
sex of the foal
twins vs singleton
which sex is carried longer? and how much longer?
males ~3 days
how much earlier are twins born?
6 days
what does acremonium do to gestation length?
incr average gestation length by 2 weeks to 20 days
define: premature foal
underdeveloped foal born early (300-320 days)
define: dysmature foal
birth of a foal at normal gestation length but foal is immature and undersized despite normal GL
what is meant by "mobile embryonic vesicle of early pregnancy?"
in order for the mare to recognize pregnancy, the embryonic vesicle must move from one end of the uterus to another
what is the maternal recognition of pregnancy?
---what is it mediated by?
Embryo MUST migrate through the uterus
-contact is achieved by mobility of embryonic vesicle
-uterine contractions move the embryonic vesicle from one end of the uterus to the other
---mediated by fetal-endometrial contact
what is "fixation," when does it happen, and what is it caused by?
-the embryonic vesicle stops moving and becomes fixed in place at the base of the horn
-by day 16
-caused by enlargement of embryonic vesicle and tone of uterus
---fixation is NOT fetal-maternal attachment
fetal-maternal attachment: what happens by day 25?
close association between chorion and endometrium
fetal-maternal attachment: what happens by day 38-40?
interdigitation between trophoblastic (chorionic) microvilli and endometrium
fetal-maternal attachment: what happens by day 45?
fetal amcrovilli appear as rudimentary structures
fetal-maternal attachment: what happens by day 150?
there is full placental attachment in the form of microplacentomes (microcotyledons/microcaruncles)
difference between the microplacentomes of the ruminant and the mare
microplacentomed of the mare are microscopic (grossly, the mare is considered to have diffuse placentation)
how are endometrial cups formed and when?
--what do they look like
day 25 - embryo forms chorionic girdle (band)
day 38 - trophoblastic cells from the girdle invade uterine epithelium to form pale, irregular (circular/horseshoe-shaped) outgrowths of the uterine luminal surface
function of endometrial cups
-secrete eCG (PMSG) --> incr P4 secretion from primary CL --> may be necessary to maintain primary CL out to 120 days
-assist in formation of supplementary CLs
when is eCG first detectable from endometrial cups?
-when does it peak?
--when is it nondetectable?
35-42 days
-55-65 days
-100-150 days
What are the clinical implications of the endometrial cups?
-if pregnancy is lost or a mare aborts after 36-40 days, she will not return to estrus until the cups regress
-w/forced estrus, often she won't ovulate
-eCG can be detectable after pregnancy loss
-lack of formation of supplementary CLs cause abortion between 70-150 days (inadequate P4 bc less eCG bc no supplementary CLs bc no endometrial cups)
at what point would an ovariectomy NOT cause abortion?
after 100-140 days
the progestins of fetoplacental origin appear in mare circulation when? increase until when?
---this means what?
-30-60 days
--300 days
---the support of the pregnancy shifts from the CL to the fetoplacental unit
how do you maintain pregnancy in ovarectomized mares?
exogenous P4 (many can maintain pregnancy w/o exogenous P4 after 100 days)
4 ways to diagnose pregnancy
palpation per rectum
on palpation per rectum during pregnancy, what size bulge will you feel:
1. Days 25-30
2. Days 35-40
3. Days 45-50
4. Days 60-65
1. hens egg (prominent uterine tone)
2. tennis ball
3. grapefruit/softball
4. cantelope
what will you see on ultrasound during pregnancy at:
1. 9-10 days
2. 20-21 days
3. 24-26 days
4. 60-70 days
1. embryonic vesicle detectable
2. embryo
3. heartbeat
4. sex determination
during pregnancy, when you you detect hCG?
between 40-120 days (look in notes, pg 23)
false negatives of hCG detection during pregnancy are common when?
when mares are carrying mule fetuses
during pregnancy, when does the estrogen concentration in the blood and urine exceed that of estrus?
by day 60-100
during pregnancy, when does circulating estrogen peak?
180-240 days
during pregnancy, where will estrogens present?
in feces and milk
at 4 months of pregnancy, what shows up in the urine which is unique to the mare?
equilin and equilenin
what 3 things are used to predict foaling
1. change in udder size and secretion (mammary gland notable in last month, filling of teats near parturition, udder engorged in the last few days, "wax" accumulates on end of teats last 1-4 days, milk leakage)
2. monitor milk secretions (fluid changes from thin yellow to milky, colostrum forms (yellow-orange), Ca and Mg incr)
3. mechanical/electronic monitoring
(pg 24)
what concentration of Ca carbonate says foaling will happen soon?
if Ca carbonate is <200ppm, how sure are we that foaling won't happen w/i the next 24 hours?
is Ca carbonate is >200, we are ____% sure that foaling will happen ___?
97% sure it will happen in the next 72 hours
how long until Oxytocin induces delivery?
15-90 minutes
what 2 drugs can be used to induce foaling?
oxytocin and prostaglandin
what is "premature placental separation" and when does it occur?
--what else is is called?
when the chorion separated from the uterus and red, velvety surface appears at vulva rather than white amnion
-occurs most commonly during parturition
--"red bag"
how do you fix "red bag?"

--what may occur?
cut the chorion and allow allantoic fluid to escape --> deliver foal w/o having to remove the chorion with it
--fetal hypoxia/anoxia
what can cause red bag:
1. midgestation
2. during parturition
1. death of a twin, abortion
2. placental edema from late gestational stress, placental edema by fescue.endophyte toxicity caused by ingestion in the last 45 days of gestation (pg 26)
when is a placenta considered retained?
when it is not expelled w/i 3 hours
what is a partial retained placenta?
--where is it more likely to occur
when a major portion is expelled w/a torn piece left in uterus (examine expelled placenta to determine it is complete)
--in the nongravid horn
what contributes to retained placenta?
dystocia, uterine trauma/myometrial exhaustion, placentitis, fetomaternal endocrine dysfunction (too little oxytocin or response to oxytocin)
what can a retained placenta cause?
metritis, septicemia/toxemia, laminitis, delayed uterine involution
how to treat a retained placenta
distention of chorioallantoic cavity w/warm saline
systemic/local antibiotics
uterine lavage
laminitis tx/prevention (cyclooxygenase inhibitors - flunixin meglumide)
uterine prolapse: common or rare?
rare (pg 27)
postparturient emergencies
uterine prolapse (rare)
invagination of the uterine horn
uterine rupture
internal hemorrhage
when is invagination of the uterine horn suspected?
-what might it be associated with?
when postpartum mare has mild colic that is unresponsive to analgesics

-retained placenta (or partial)
when does uterine rupture usually occur?
-what might it result from?
--what does it cause/signs?
during 2nd stage labor

-from dystocia or manipulation

--hemorrhage and pain, colic signs, depressed, febrile, blood loss, peritonitis
how do you diagnose uterine rupture?

--how do you treat it?
palpation per vagina (uterus too large to palpate all of it), abdominocentesis

--laparotomy and surgical repair
what might cause internal hemorrhage postparturition?

-more common on which side?

-- more common at what age?
rupture of uterine artery or utero-ovarian artery (less common is the external iliac artery)

-right side

-- >10 years old
signs of internal hemorrhage?


-what may be found on subsequent prebreeding examinations?
severe colic, sweating, evidence of hemorrhagic shock, or no CS at all

difficult (control activity/excitement) - analgesics, corticosteroids for shock, blood transfusion

-hematomas on the broad ligament
many twin pregnancies result in abortion of both twins around what time?
6-8 months (anywhere from 4 months to term)
after a double ovulation, with a 50% conception rate, what % chance does the horse have of conception of:
1. no embryos
2. one embryo
3. twins
1. 25%
2. 50%
3. 25%
when can twin pregnancies be determined by U/S?
14-18 days after ovulation
if both twins are in the same horn (unilateral), what is the % chance of elimination of 1 twin?
the majority of twin elimination occurs when?
--what happens if neither twin aborts before this time?
before 40 days
--they will most likely both be carried until abortion occurs later in pregnancy
what is pinching and when should it be done? why?
the way to eliminate one twin
--should be done by U/S at 14 days before the embryos are fixed at day 16
---to eliminate the waiting game to see if they will become unilateral or bilateral
what do you do if twins are present at 32 days?

--what do you do if you want to breed the mare again next season?
either abort both before endometrial cups form or let them go to see if one will be aborted w/i the next month

--abort at 32 days
if this is the last breeding season of the mare and twins are still present at 32 days, what do you do?
watch them as far as 60 days to determine if one will be eliminated --> if not eliminated, abort to eliminate the possibility of damage from alter abortion
methods of eliminating one twin in later gestation
-aspirating fluid from one fetal sac
-intrafluid/intracardiac inj of KCl using a transvaginal U/S guided needle
signs of impending abortion
-vaginal discharge
-bagging up of the udder
-perineal relaxation
-U/S evidence
Tx for impending abortion/premature parturition
-Progestagens (Altrenogest, oral, SID)
-antibiotics (Trimethoprin sulfa)
-Isoxsuprine (prevents uterine contractions)
-stall rest, intranasal O2, constant monitoring for signs
organisms commonly involved in ascending placentitis
Strep spp
Staph spp
E. coli
Pseudomonas spp
Klebsiella spp
Aspergillus spp
Mucor spp
-rare: Candida
ascending placentitis is more common in mares w/ ?
poor perineal conformation, small cervical tears that relax toward the end of pregnancy
-can also occur in assoc w/colic sx
bloody vulvar discharge at end of pregnancy can mean: (2)
-ascending placentitis
-in older mares, often due to a vaginal varicosity !!
true or false: always do a vaginal exam on a pregnant mare
FALSE: unless in active labor, avoid vaginal exam since this may result in ascending placentitis or abortion in an otherwise healthy mare
define: hydrops

--happens during what time?
excessive fluid accumulation usually w/i the allantoic or amniotic cavities (relatively rare)

-6-10 months
signs of hydrops
-dramatic abdominal enlargement w/i a 2 week period
-difficulty moving around/getting up/lying down
-marked ventral edema
-dyspnea, incr HR
-NORMAL temp
what might you find on a transrectal palpation of hydrops?
enlarge uterus w/dorsal wall protruding over the level oft he pubis
-usually can't palpate the fetus
-more progressive enlargement than twins (d/dx)
what will usually happen w/hydrops
will usually abort spontaneously (though should terminate bc could cause rupture)
what occurs in congestive brain swelling?
vasodilation of capillaries and venules, hypercapnia
w/hydrallantois (hydrops allantois), why is the prognosis usually guarded?
believed to be hereditary so try a different stallion next time
which is more rare: hydrallantois or hydramnion?

--which usually results in a more dramatic incr in fluid?

the equine rhinopneumonitis virus is a ___ virus
equine herpes virus (EHV-1)
most common cause of infectious abortion in the mare during the last half of gestation ***
EHV-1 (equine rhinopenumonitis virus)

-usually after 9 months, but can cause abortion as early as 5-6 months
what can EHV-1 cause? ***
abortion, respiratory dz, neonatal mortality, neurological dz
EHV-2 causes
respiratory dz in foals
EHV-3 causes
equine coital exanthema (venereal herpes)
EHV-4 causes
respiratory dz and sporadic abortion
How is EHV-1 transmitted?

inhalation/contact w/infected secretions --> initial replication in URT --> viremia --> endometrial invasion --> placental edema + separation of the chorioallantois --> fetal anoxia/death (fresh at expulsion w/minimal autolysis)
EHV-1 can is a ____ virus?
recrudesce (resting) virus - can cause a latent infection bc may reactivate and shed during stress
clinical presentation of EHV-1
--presentation in fetus
---what will you see histologically and microscopically in the fetus
abortion in an otherwise healthy mare, though it can cause respiratory infection in young horses

--icterus, SQ edema, scattered petechiae, hydrothorax, hydroperitoneum, pul edema
---greyish necrotic foci in liver, adrenals, spleen, thymus, lnn; viral eosinophilic intranuclear inclusiong in nectoric foci of organs
EHV-1: when does abortion occur?
usually in late gestation
EHV-1: how do you diagnose this?
-paired sample 2-4 weeks apart, with a 3-4 fold incr
-neutralization/ELISA of fetal sample
-viral ID from nasal swabs of fetal tissues (IFA or PCR)
-gross path & histopath
EHV-1: how do you prevent? when? problem?
-vaccination @ 5, 7, and 9 months using killed or modified live vacc --> problem: not 100% effective and short-lived
-pregnant mares should be kept stress free, isolated from incoming horses
-isolate those w/respiratory dz and who've aborted
-clean and disinfect areas
EVA (equine viral arteritis): endemic in which breeds? who is the carrier?
-standardbreds and warmbloods

--stallion is the carrier (can carry the virus in semen from weeks to years)
EVA: transmission, signs
-inhalation or venereal (tropism for endothelial cells) --> edema & hemorrhage
-in pregnant, will also spread to the uterus --> necrotizing myometritis --> placental detachment --> fetal death (fetus not always infected by the time abortion occurs)
EVA: when does abortion occur?
usually 7-10 days after infection and is most common in 2nd half of pregnancy
EVA: diagnostics

-REPORTABLE in many states

-same serology as EHV-1 (paired titers)
-viral ID from nasopharyngeal swabs and fetal lung and spleen by IFA
-histopath: necrotizing myometritis from endometrial biopsy

--lesions rare in fetus (if present, usually necrotizing vasculitis)
(most asymptomatic)

fever, nasal discharge, dyspnea, diarrhea, etc
EVA: prevention
-mainly by vacc (modified-live) - don't like this bc will test (+) from vacc then can't be shipped internationally
-all stallions should be tested before mating
EVA: what does a negative serology mean?
-assumed not to be carriers and can be vaccinated (booster annually if <1:4)
EVA: what does a positive serology mean for a stallion?
-should be tested for shedding (virus isolation from semen)
-shedding stallions should be vaccinated and retested to determine if status has changed

(pg 37)
CS of leptosporosis in pregnant mare
-rarely seen in aborting mares: pyrexia, icterus, anorexia, depression
what does lepto cause in pregnant mare? which serotype?

--most common non-host adapted serovars in N America
-sporadic abortion, (stillbirths, premature live births)

-Bratislava (horse = maintenance host)

-- kennewicki (Pomona-type), grippotyphosa (raccoons), hardjo (cattle), canicola, icterohemorrhagiae, sejroe
w/Lepto, when are abortions seen?
abortions 1-3 weeks after CS (if CS are present)

most commonly in late fall (Nov, Dec) in wet conditions

> 6mo of gestation
when was the last time Salmonella abortus equi was diagnosed?
not since the 1930s
diagnoses and prevention of lepto
-serology of serum or fetal fluids, lepto from urine

--no vaccines, isolate and clean
CEM (contagious equine metritis): being eradicated where?
N america

--recognized in Europe in mid-70s, in USA in late 70s
CEM: organism causing dz
Taylorella equigenitalis (small coccus, grows microaerophilically)
--not routinely picked up in standard cultures bc requires 5% CO2
CEM: signs in stallions

--where can it be found?

--can persist in repro tract for months-years (particularly in urethral fossa and the associated sinus)
CEM: signs in the mare ***
-very high morbidity (almost every mare mated to infected stallion gets it)
-no mortality seen
-purulent discharge from vulva 48hrs to 14 days after (most infn's apparent @ 10-14 days)
-severe endometrial inflamm (most apparent 14ds after infn)
-short cycling (luteolysis)
-conception failure
CEM: control features that require vet interveition
-testing mare/stallion genitalia when imported
-clitoral sinus removal (harbors T. equigenitalis and can withstand tx in sinus)
-fastidious, so complicated detection (some us PCR in eradication programs)
-susceptible to disinfectants
-NO vaccine
be able to list additional viral/bacterial/parasitic dz of the repro system in horses:
-EIA: can cause abortion associated w/the acute febrile dz in pregnant mares
-Trypanosoma equiperidum can causea venereal dz called Dourine (eradicated in europe and N america
-Coital exanthema (EHV-3 venereal dz) not usually assoc w/abortion/infertility but characterized by vesicles and ulcers on vulva and penis
-Salmonella abortus equi not a factor in recent history (used to cause abortions a century ago)
-Strep zooepidemicus found in external genitalia (mares and stallions) - common cause of vaginitis, cervicitis, and metritis - Streptococcal placentitis can lead to abortion
pathological changes in: endometritis
inflamm !!! (if there is no inflamm, there is no endometritis)
-elevated lymphocytes
-eosinophils in tissue or lumen
pathological changes in: periglandular fibrosis and nesting of endometrial glands
-uterine glands age and degenerate (surrounded by collagen laid down by fibroblasts
-glands nest together, dilate, atrophy
-irreversible fibrosis assoc w/incr prabability of embryonic death
-cystic glandular distention
in which pathological change of the endometrium will you find cystic glandular distention?
periglandular fibrosis and nesting of endometrial glands
What are lymphatic lacunae?
-pathological changes in the endometrium - distension of the lymphatic ducts
-not sure of the effect on fertility
when will you see edema of the endometrium?
normal in estrus
when will you see atrophy of the endometrium?
-normal in anestrus
-old mares that have stopped cycling
-mares w/gonadal dysgenesis
list some pathological changes you may find on an endometrial biopsy
periglandular fibrosis & nesting of endometrial glands
lymphatic lacunae
atrophy of the endometrium
reasons why a physical clearance of bacterial contamination in the uterus may be difficult after persistent mating
-delay of myometrial activity
-bad angles between vulva, cervix, and uterus
-repeated contamination
-uterine lymphatic drainage impaired
-endometrial vasculature degeneration
most young mares clear infections of Strep zooepidemicus. What happens w/barren infertile mares after persistent matings?
unable to clear infection --> prolonged inflamm reaction --> baggy, thickened uterus on palpation per rectum
persistent matings: problem w/uterine secretions in the mares and bacterial contamination?
the secretions interfere w/efficienct of neutrophil phagocytic function
persistent matings: what is a big factor of physical contamination clearance impairment?
age (called a "delay in uterine clearance")
how to diagnose endometritis induced by persistent matings
-history, poor perineal conformation, mare accumulates fluid after mating, vaginal speculum exam, uterine cytology, culture, and biopsy
two ways to treat endometritis induced by persistent matings
1. remove intrauterine fluids after breeding (lavage 4 and 12 hrs after breeding, oxytocin IV, clopsostenol)
2. antibiotics (intrauterine is controversial) - saline lavage and PGF2a gave superior results
pyometra in the mare is defined as
an accumulation of large quantities of inflammatory exudates in the uterine lumen causing uterine distension (not the same as in a dog or cow)
-there could be interference w/normal drainage of fluid from the uterus
-open or closed
what can occur during pyometra?
normal cyclicity may continue or CL life may be altered by early PGF2a release (due to endometrial inflamm) or failure of luteolysis (due to endometrial pathology)
treatment of pyometra
lavage of uterine lumen
--if nonresponsive --> hysterectomy
most common ovarian tumor
granulosa cell tumor
what cells does the GCT (granulosa cell tumor) come from?
theca cells
what c/s will you see w/a GCT
-unusual behavior - stallion-like
-constant estrus
GCT: what will the ovaries look like?
-atrophy of contralateral ovary
-enlargement or absence of the ovulation fossa in the affected ovary
-on U/S - honeycomb appearance (multilobulated interior)
GCT: what will you see diagnostically?
-testosterone high (in 50%)
-incr inhibin
-low progesterone
how do you treat a GCT?
rare ovarian tumors?
teratoma, arrhenoblastoma, serous cystadenoma
where may a hematoma of the ovary form?
in anovulatory follicle
when are large follicles nonpathological?
-transition follicles may get large and fail to ovulate
-follicles in pregnant mare
-normal estrus follicle
congenital abnormalities causing infertility
turner's syndrome, ovarian hypoplasia, testicular feminization
components of a Stallion Breeding Soundness eval
-ID, Hx, PE, test for viral dzs (EIA Coggins, EVA serology or virus isolation on semen)
-semen collection and eval of libido, mating ability
-semen eval (total sperm [vol x conc], motility [total & progressive, velocity, extended motility, longevity [both raw & extended])
-morphology (neg stained prep, wet fixed prep)
why are two sample ejaculates collected for eval?
--what qualifies a set of ejaculates as "representative"?
second should have 50-60% of sperm of the first

--if the ratio is "typical," the ejaculates are "representative"
how long must you collect ejaculates to get the Daily Sperm Output (DSO)?
daily for at least a week
how many mares does a stallion breed normally? how many can be bred w/AI?
-40 mares

-120 mares
what two bacteria are you mainly looking for on a stallion culture?
-pseudomonas aeruginosa
-klebsiella pneumoniae
culture sites
-urethra pre-ejaculate
-urethra post-ejaculate
-semen (plus EVA culture for shedders)
what does Taylorella equigenitalis cause? how do you culture for it?
-Contagious Equine Metritis

--swab prepuce, urethra sinus, fossa glandis
---it is REPORTABLE (US is free of dz at present) - culture must be sent to state/fed diagnostic lab
expected BSE results:
PAGE 45-6 !!!
most common neoplasia of the penis
an inguinal cryptorchid is aka ?
high flanker
hormone assays used to tell if there is a cryptorchid horse or if it has been castrated
1. testosterone (<40pg/mL - no testicles, >100pg/mL = testicular tissue)
2. hCG (10,000units hCG admin, serum/plasma testosterone conc incr 2-3 fold = testicular tissue present)
3. estrogen in horses 3 yrs or older (>400pg/mL - testicular tissue present)
how to tx cryptorchidism
complete castration