Exam 2- foaling continued Flashcards
How long should expulsion of the placenta take
Less than three hours
Why do we tie the placenta up
It helps weigh the placenta down to be passed naturally- do not pull!
What are the red flag in stage three
The placenta takes longer than three hours to pass or the chorion is on the outside
What should the placental colors be
Chorion is red, allantois is pink
Why do we weigh the placenta
A super heavy placenta is a sign of inflammation- it should be 10% or less of the foals body weight
What do we look for health- wise on the placenta
look for healthy signs on the chorion surface and ensure the placenta is complete
Gravid horn vs non gravid horn on the placenta
gravid horn is where the back legs of the foal were, should be thicker- non gravid horn is thinner
Hippomane
An aggregation of minerals, feels like hard dough, free floating in the allantoic fluid
Normal placental findings that lack villi
Cervical star, allantochorion pouch, insertion of cord
Normal placental findings with villi
Appropriate autolysis, yolk sac remnants, allantoic pouch
Appropriate autolysis
Shows on the placenta where it takes awhile to detach (bright red shows the area that last detached, first detached is brown
Large avillous regions
happens in twin pregnancies where placentas are against each other- can also come from mare having uterine cysts
o Abnormal Density of Villi
villi are not very dense- will impact the amount of nutrients foal will get- uterus is not healthy enough for villi to attach
o Placentitis
- inflammation of the placenta (looking on chorion surface) looks like thick layer of snot on placenta- could be fungal or bacterial infection (low pregnancy rates and early abortion)
Thickened Placenta
caused by fescue or placentitis
Placental Hemorrhage
can be a sign of trauma during delivery- hematoma in allantois
Meconium Staining of Amnion
foal poop in amnion-can be a sign of fetal distress- danger for the foal if inhaled (sets up for pneumonia) we assume its in foal lungs already
Ascending placentitis
bacteria enters the vagina/cervix and affects the cervical star (foal exposed to bacteria) – can work its way backwards to the rest of the placenta
Retained placenta
hasn’t passed in three hours
Retained placenta treatment
give oxytocin injections on farm, causes contractions to release placenta- at three hours call the vet (lavage- stick a large tube in the placenta and blow it up enough so the microvilli will detach
Concerns of retained placenta
Laminitis- Mare will go on antibiotics and laminitis prevention (ice boots on mare- replace every 1-4 hours)
Rare delivery complication- Uterine tear
tearing of the uterus- can be repaired surgically
Rare delivery complication- Hemmorage
artery wall gets weakened and ruptures during delivery (if a mare is hemorrhaging you do not see blood its internal bleeding) look at mucous membrane coloration- will not be pink
Rare delivery complication- perineal laceration
Perineal laceration- foal during delivery damages the rectal lumen in worst case scenarios (tears in vaginal mucosa) surgery will be done to fix tear
Pain relievers for post partum care
- banamine most common (given after the placenta has passed) blocks prostaglandin so the placenta would be kept inside
Mare fecal output
should defecate at least 12-18 hours after foaling (have vet check after 24 hours, might be tubed with water to reduce risk of impaction colic)
Feeding
do not feed until the mare defecates
Deworming
o Deworming- if the mare is current on deworming, no need to take action- if not dewormed then deworm 12-24 hours after foaling (mares can pass threadworms to foals)
Involution
the uterus shrinks to normal size and the endometrial lining is repaired
What helps involution
Oxytocin and excericise
Lochia
discharge from the mares reproductive tract from the result of the endometrium healing
Brown reddish color, in the first 10 days
Eponychium
- soft on layer on bottom of hooves feet that falls off when they stand (protects mares repro tract during delivery)
What to do if umbilicus bleeds
some blooding normal, umbilical clamp if it does not stop
Treatment of chlor vs iodine on umbilicus
dip umbilical cord in dilute chlorahexadine (1 part chlor, 4 parts water) repeat treatments or iodine (one time treatment) very quickly dries up the stump but can also trap bacteria in the cord
Why do we tear the cord and not cut
So the umbilicus will clot
Sternal position
within 10 minutes
Suckling reflex
15-30 minutes
Up on own
1-2 hours
Nursing
2-3 hours
Begins passing meconuim
4-6 hours (monitor)
Urination
12 hours (monitor)
Patent urachus
patent urachus might stay open and urine could drip from the umbilical cord – most of the time it closes on its own- higher risk for infection
Mare hygiene
Wash udder
Monitor mare for what after foaling
Signs of comfortability
What is banking colostrum
Freezing colostrum from high milk and percentage candidates
Banked colostrum processing and utilization
Put the milk into a container and filter it, label then warm up slowly in water bath to use
Gut closure
Starts as early as 8 hours- ends at 24 hours
What is the timing of passive transfer
Early- 8-12 hours, late- 18-24 hours
Goal for early transfer
400-800 mg/dL- colostrum or plasma if low
Goal for low transfer
> 800 mg/dL, plasma if low
Foals at high risk from failure of passive transfer
Agalactia, prelactation, sick or injured neonates, poor quality colostrum
Foal feces
Meconium then milk feces (12 hours after birth)
Preventing meconium colic
Enema- lavage the rectum (fleet enema or soapy water enema)
When do we give foals medication?
Only if its veterinarian recommended, depends on environment, can lead to GI upset
What medications are given to foals at risk of bacteria exposure
Bio sponge and metronidazole (clostridium treatment)
Neonatal red flags
Foals sleeping standing up (uncomfortable) or not nursing
Colicky behavior in neonates
Sleeping on their back, with legs close and tucked, neck arcing
Angular limb deformalities
Valgus (knees turned out) varus (knock kneed)
Flexural deformities
Contracture and laxity (loose tendons, dysmature foals tend to have laxity)
Trans uterine fold job
Prevents urine from dripping back into the repro tract
Urethral opening job
works with the trans uterine fold to move away urine flow
Parts of the vulva
Labia, clitoris, dorsal and ventral commisures
Vestibule
From external labia lips to urethra- hymen
Vagina
Collapsed lumen, highly distensible
Pneumovagina
Abnormality where air gets into the vagina- can be fixed with a Caslick’s procedure (suturing a portion of the labia lips)
Problems with a pneumovagina
Bacteria can enter where air is getting into the vagina
Profolactic caslicks
Caslick’s given to young horses in training to let less air into the vagina during exercise
Unique aspects of cervix (smooth muscle)
Longitudinal mucosal folds- stallion can deposit semen in the cervix
Cervix change during diestrus
Lots of tone, pale color
Cervix change during estrus
Very red in color (vascular), very relaxed
3 anatomical barriers of defense
Vulva, vestibule, cervix
Uterus characteristics
Bicornuate,
Uterus in diestrus
Endometrial folds are flattened with lots of tone
Uterus in estrus
Endometrial folds get edema and swell
Oviducts
Site of fertilization
Mare ovary shape vs other species
Mares is kidney shaped- other species spherical
Mesothelial lining vs other species
Covers just stalk in others, whole ovary in mare
Medulla location vs other species
Medulla on the outside for other species, inside for mare- follicles grow on inside
Ovulation points vs other species
Other species can ovulate at any point on the ovary- ova fossa for mare
Medulla
Vascular
Cortex
Follicles
What does the ovulation fossa do?
reduces twin pregnancies- follicles become teardrop shaped as they move toward the fossa
Corpus hemorrhagicum
Forms where a follicle has ruptured (fresh ovulation) turns to a Cl as it matures
Corpus luteum does what
Secretes progesterone
Theca interna cells secrete _ while granulosa cells secrete _
Androgen, estrogen
What is a graffian follicle
An ovulatory follicle
Onset of puberty
12-15 months
Estrous cycle length
21-23 days, about 16-17 days in diestrus
Actual heat/estrus length
4-6 days- highly variable
Time of ovulation
24-48 hours prior to the end of estrus
Ovulations per cycle
1, but horses can double and triple ovulate
Foal heat
Unique, horse cycles 5-16 days post foaling (endometrial repair must be going on)
Estrous cycle detection
Most critical aspect of breeding management
Ultrasound advantages/ disadvantages
Transrectal ultrasound, see exactly what the horse is doing, machine is expensive- lots of training to learn
Solid white tissue
Hyperchoic
Black fluid
Anechoic
Hemorrhagic anovulatory follicle
Stay for months- seen more at the ends and beginnings of seasons
Fluid in the uterus
Sign of inflammation
Teasing
Seeing behavioral signs of estrus
Mare in estrus signs
Urinates, steps wide, tilts pelvis down, winking
Mare in diestrus signs
Squeals at stallion, aggressive kicking or biting behavior- ignoring
Estrus behavior impacted by what
Herd dynamics, wet mare (lactating) silent heat (never shows signs)
Individual teasing
One stallion and one mare (most accurate and time intensive)
Group or pen teasing
One stallion in a group of multiple mares (time efficient)
Chute teasing
Stallion is in a stall while mares are walked through a chute
Self teasing
Mare and stallion are on opposite sides of a fence unrestrained
Stall teasing
One horse is in the stall while the other is in the aisle
Rail, fence, or wall teasing
Both horses are separated by a barrier
Cage teasing
Stallion is in a cage in a field while mares can approach him freely
Seasonally polyestrous
Have multiple estrous cycles that happen in a given season- long day breeders in summer
Natural ovulation peroid
April to September
Transition periods
Erratic estrous cycles, erratic growth of follicles, ovulate small follicles
When is the anestrous peroid
During deep winter- ovaries are vary small- hormones shut down
Dark periods
Create more melatonin, melatonin inhibits repro system, decreased hypothalamic pituitary ovarian axis
Other factors of seasonality
Multiple hormones, hemispheres, domestication (domesticated horses tend to cycle year round)
Estrus phase (follicular phase)
4-6 days, secreting estrogen, follicle on ovary, behavioral signs, ends with ovulation
Diestrus phase (Luteal phase)
Corpus luteum on ovary, progesterone is secreted, non receptive towards stallion, ends with release of prostaglandin
Growth of Cl
Outer cells start to weaken and membrane ruptures when oocyte leaves, it takes 5 days for granulosa cells to form luteal cells- produce progesterone
Growth, maturity, and regression of CL
0-5 d (G). 6-13 d (M). 14-16 d (R)
HPO axis
Hypothalamic pituitary ovarian axis
FSH
Released from pituitary, targets the granulosa cells of the follicle, promotes follicle growth and increases inhibin and estrogen levels
LH
Released from pituitary, targets the theca interna cells of the follicle, surges with high inhibin and estrogen levels- increases androgen production, follicle maturation and promotes CL formation
Why is estrus most variable
It depends upon the size of the follicle (bigger follicle, faster ovulation)
Why do horses have two follicular waves
Ensures there is one large follicle compared to the others
Follicular wave growth (after ovulation)
In between waves, inhibin causes follicles to shrink, then FSH causes follicles to grow (wave ends at day 10 then another forms)
Dominant follicle size in follicular waves
starts at 22 mm in size, dominant follicle is receptive to LH, produces estradiol and inhibin
Prostaglandin F2 alpha
Produced by uterus, released if no MRP, targets luteal cells of mature CL, causes luteolysis
PGF2A unique to equine
Travels from uterus through peripheral circulation to ovary (little metabolized in lungs, increased reaction to prostaglandin)
Estrogen (ovarian hormone)
secreted from theca interna and granulosa cells of follicle, targets the hypothalamus, pituitary, brain and repro tract, relaxes the cervix, prepares for pregnancy, regulates GnRH, FSH and LH, increases uterine edema and motility, sexual behavior
Inhibin (ovarian hormone)
From granulosa cells of the follicle, targets the anterior pituitary, inhibits FSH and helps with selection of dominant follicles
Progesterone (ovarian hormone)
From luteal cells of CL, targets hypothalamus, uterus and mammary glands, maintains pregnancy (tightens cervix), mammary growth and secretions, regulates LH via GNRH
Inhibin and FSH relationship
Inverse- one is up while the other is down
Agonist
similar enough to facilitate similar results (can bind to same receptor)
Antagonist
Similar enough to bind to the receptor, but it blocks the receptor instead of performing function
Why use artificial lights
Induces early cyclicity- allows breeders to get foal dates as close to January 1st as possible
1st ovulation when using lights
60-90 days after onset (1-2 weeks faster with hormones but not cost effective)
treatment timeline with Artificial lights
Start breeding February 14th, start under lights at thanksgiving, horse gives birth next January
Light sources
Equilume ($400-500) masks with light under one eye, 100 W bulb on timer (14 and a half hours of total daylight) should light enough to read in all corners of stall
Lighting protocols
Add to existing daylight to equal 14.6-16 hours, use one hour of light that occurs 9.5 hours after sunset
Domperidone
Dopamine agonist, induces prolactin, blocks the effects of dopamine, oral ($20 per 5mL daily dose 110 mg/mL) sulpiride injectable
Estradiol cypionate- an estrogen agonist
Commonly used in ovariectomized mares, induces estrus behavior, (injectable)
Oxytocin
Short half life, rids inflammation in the uterus, helps with uterine contractions, milk let down, induces parturition- usually injectable IM, 10-20 IU give every 4-6 hours (1/2-1 mL)
Common reasons mares won’t settle
Improper timing of breeding or post breeding endometritis
Post breeding endometritis
Inflammation of the endometrium in the uterus (some mares cannot fight inflammation from sperm) higher risks for old olden mares
Management steps for post breeding endometritis
Use of semen extender with antibiotics- helps to prevent contamination
2) Less frequent breeding /decrease volume of breeding– can time to breed once instead of multiple matings 3) Lavage with saline- flush in sterile saline then removing it – can start 4-6 hours after breeding
4) Induce uterine contractions – oxytocine or cloprostenol (stays in the body longer than oxytocin) Activity!
5) +/- dexamethasone treatment- anti inflammatory (reduce mare’s inflammatory response in uterus)
Prostaglandins
Induction of luteolysis (short cycling) shorting diestrus- IM only
When is using prostaglandin effective
About 5 days after ovulation when the CL is mature
What determines the return to estrus
Usually 3-5 days, depends on the waves- if we don’t know where they are in the wave cycle, we do not know the ovulation/ heat timeline
Why are prostaglandins IM only?
not metabolized quickly (not safe IV because it will be a heavier dosage all at once vs IM- colicky) mares get sweaty for about 30 minutes – give early morning or late night when less hot out, move injection site outside
Dinoprost tromethamine
Lutalyse (prostaglandin) Dose of 1-2 mL or 1/10 mL 24 hours apart (minimize side effects)
Cloprestonol sodium
Estrumate (prostaglandin) dose of 1 mL, slightly longer half life with less side effects (more expensive)
LH/GnRH
Releases an LH surge, induces ovulation, ovulates 24-48 hours after administration, long surge achieved by slow release drugs/ capsules, 24 hour long effect
What needs to be present for LH/GnRH to have its effect
a 35 mm follicle and edema present
Human chorionic gonadotrophin (LH agonist)
80% effective, 1,500-2,500 IU IV dose, horses start to develop antibodies against it (use twice a year)
Deslorelin (GnRH agonist)
80% effective, works in a greater number of mares, 1.8 mg IM (slow release gel) $60 a dose-expensive
Recombinant equine LH
Produced in a lab setting, acts like equine LH, long half-life, Equipure reagent for veterinarians- 90% effective
Progesterone
Inhibits LH, induction of luteal phase,
3 uses of progesterone
Pregnancy supplementation- on till 120 days of pregnancy
Used to suppress estrus (handy for show/performance horses)
Estrus synchronization- synchronizing stallion with mare, recip and donor mare synched up
Oral synthetic progestins
More labor intensive, covers bases every day vs capsule
Altrenogest (oral progesterone)
2.2 mg/ 100 lbs daily, wear gloves absorbed easily
Compounded injectable (progesterone)
Less labor intensive, 150 mg per day IM, Encapsulated form can last weeks, $3.00 per day- rate of decrease is different in every horse
Progesterone and estradiol
widely used to synchronize embryo Transfer mares (inhibits FSH and LH) shut down all gonadotrophins follicles and ovaries will be small – can now synchronize follicle growth and will be at the same size when they start
Negative feedback on Gonadotropins
Progesterone and estradiol compounded injectable
150 mg progesterone + 10 mg estradiol per day IM
$40 once (every 7-10 days)
Estrous synchronization P+E protocol
Very tight synchronization- $100 a horse
Estrous synchronization protocol- just progesterone
$22 a horse
Why is equine superovulation useful
Induces multiple follicles to grow at the same time, increases odds of success when working with reproductive technology (all protocls must use FSH)
Equine pituitary extracts) EPE)
Grind pituitary and remove other hormones- not readily available due to contamination concern
Equine FSH (eFSH)
taking pituitary extract and purifying in the lab (not readily available)
Recombinant equine FSH
Reagent for verterinarians
