Equine - Parturition and Normal Neonate Flashcards
Typically, how long is gestation in a mare?
340 days (average is 338-343 days)
What is the average gestation length for Thoroughbred and Standardbred horses?
325-340 days
How long is average gestation in Draft mares?
350-375 days
Mares bred in late winter and early spring have gestation lengths that are on average 10 days _____ than those bred in summer.
longer
Mares with fillies foal on average ____ days earlier.
three
True or False: Mares will often carry a foal for a similar time period during each pregnancy.
TRUE
How is a due date of a mare calculated?
Approximate foaling date may be calculated by subtracting 25 days from the day the mare was bred or ovulation was detected - the date is more accurate when actual breeding or ovulation date is known
How should pregnant mares be housed?
they should be separated from other horses
How are pregnant mares managed?
Light exercise is encouraged during early to mid pregnancy, avoid stress, and routine dental and foot care is recommended to be performed following foaling and prior to breeding
When should a mare be moved to a stall prior to foaling?
7-14 days prior
What nutrition changes are necessary at early to mid gestation?
none - just make sure there is a good quality pasture or hay +/- supplement
What is the foal growth rate during early to mid gestation?
0.2 lb/day
What feed changes need to occur during late gestation and lactation?
increase the feed by 50-100% - good quality pasture or hay with grain mix supplement
What is the foal growth rate during late gestation and lactation?
1 lb/day
What should not be fed during the last 2-3 months of gestation?
fescue hay or pasture
What vaccinations should a mare get?
EHV-1, Tetanus, EEE, WEE, Influenza, WNV
When should the EHV-1 vaccination be given? What type of vaccination is it?
5, 7, and 9 months of gestation; killed vaccination (Pneumabort-K and Prodigy)
When should the Tetanus, EEE, WEE, Influenza, and WNV vaccinations be given/
4-6 weeks prior to foaling
What additional vaccinations could be given during pregnancy to a mare?
EVA, Strangles, Botulism, PHF, Rotavirus, and Rabies
What is the general recommendation for giving an anthelmintic during pregnancy?
Give a ivermectin-type anthelmintic one month prior to the anticipated due date - make sure to read the label
What is a Caslick’s surgery?
a surgical procedure to partially close the dorsal portion of the vulva
When should a Caslick’s be removed?
7-14 days prior to the predicted foaling date
What happens if a Caslick’s is not removed?
Dystocia and/or serious injury to the perineal region of the mare
When do relaxin levels rise, what produces it, and what to rising levels of it do?
The placenta produces relaxin and levels rise in the last 1/2 of gestation. It causes vulvar elongation and ischial (tail head) sinking
What is prolactin produced by, when do prolactin levels increase, and what changes does it influence?
It is produced by the hypothalamus 4-6 weeks before foaling and influences mammary development
What is oxytoxin produced by, when is it produced, and what does it influence?
It is produced by the pituitary at the time of foaling (Fergusen’s reflex) and influences milk letdown
When you see waxing on a mare’s mammary glands, what does that indicate in relation to when parturition is?
She will probably foal in 1-2 weeks
What will happen to K and Na levels in the milk 24-48 days prior to foaling?
K increases and Na decreases
What happens to Ca levels 24-72 hours prior to foaling?
they will increase
What can be used to measure monitoring foaling pre-partum?
Tocodynamometer - it is not common, expensive, and not practical
What initates parturition?
Fetal stress - an increase in fetal CRH may trigger a shift in placental steroidogenesis from progestins to estrogens which will increase uterine contractility and relaxin production
When does fetal plasma cortisol rise prior to parturition?
48 hours
When are the peak hours typically for parturition?
between 11 pm and 4 am
What devices can be used as foaling aids to help detect when a mare will foal?
Foalert system, intravaginal sponge, cameras, and positional sensor
How does an intravaginal sponge aid in detecting foaling?
There is a microchip within a sponge that senses temperature drop and sends alert
What does a positioinal sensor do?
It sends an alert when a mare lies down flat
How long does stage one of parturition last?
1-4 hours
What happens during stage one parturition?
cervical dilation and fetal repositioning
What signs does a mare show during stage one of parturition?
restlessness, mild discomfort/colic, and sweating
How long does stage two parturition last?
5-70 minutes - the average is 20 minutes
What occurs during stage two of parturition?
foaling - the mare moves to lateral recumbency, the chorioallantoic ruptures, and there is intermittent pushing with 2-3 minute rests
When should the amnionic sac appear during stage two of parturition?
within 5-10 minutes
What occurs during stage three of parturition?
expulsion of the placenta
When should stage three of parturition be complete?
within 3 hours
What is a very important thing to do after stage three of parturition?
to examine the placenta
How much should the placenta weigh?
less than 15% of the foals weight
What are the three layers of the placenta?
amnion, chorion, and allantois
What is the amnion and how should it appear?
it is the fetal sac and it should be so thin that you can read a newspaper through it
What does meconium staining on the amnion indicate?
fetal stress
What plaques are normal to be found on the amnion? Abnormal?
amnionic plaques are normal, fungal plaques are not
What is the chorion and what does it look like?
It is the microcotelydonary attachment to the uterus and it is velcro or fuzzy red
What can an abnormal color or appearance of the chorion indicate?
there may be placentitis
Where is the most likely place for the placenta to be retained?
the tip of the non-gravid horn of the placenta
When is the absence of villi normal?
It is normal where uterine tubes enter the uterine horn, the external cervical os enters the uterine body, and where endometrial cups existed
What is the allantois and what does it look like?
It is a layer of the placenta that is opposite of the chorion - it is located on the side towards the fetus/amion - it is smooth, light pink
What is the length of the umbilical cord and what may a short cord predisopose the foal to?
It is 50-60 cm long and a short cord may predispose the foal to an umbilical hernia
Is twisting of the umbilical cord normal?
some twisting is normal
What can torsion, or excessive twisting, lead to?
fetal death or predisposes to cystorrhexis (ruptured bladder)
What structures are located in the umbilical cord?
there are two arteries that originate from each uterine horn, vains, lymphatics, urachus, and the yolk sac
What are the indications for induced parturition?
maternal compromise (hydrops or rupture of prepubic tendon), history of red bag delivery, severe trauma at foaling, neonatal isoerythrolysis, and a history of primary uterine inertia
What is neonatal isoerythrolysis?
It is like a hemolytic anemia where the mares antibodies attack the foals blood
What is the criteria for inducing parturition?
They have to be >320 days of pregnancy, relaxation of sacrosciatic ligaments and vulva, full udder with colostrum filling teats, cervical dilation, and fetal maturity needs to be assessed
What can be used to induce parturition?
oxytocin and cloprostenol
What is the protocol for using oxytocin to induce parturition?
Give oxytocin IM and repeat once at 20-30 minutes if signs of 1st stage labor are not observed. Re-examine to determine fetal posture first. Never use higher doses
When should the second stage be complete if oxytocin is used to induce parturition?
it should be complete within 1 hour
When giving cloprostenol (Estrumate) when should stage 2 of parturition be observed?
within 4-24 hours of the injection
If you can do this safely, what should you do after a foal is born?
quietly approacha and remove the amnion from the foal’s face
Should you break the ambilicus?
no -if you must then only break 5 cm of it with gloves
When observing a mare and its foal from the distance, what questions should you ask yourself?
Is the mare being attentive? Aggressive? Is the foal sternal?
What is the 1-2-3 rule?
The foal should stand at its first hour of life. It should nurse at its 2nd hour of life. It should pass meconium at 3 hours of life.
When should a foal be in sternal recumbency?
within 5-10 minutes of life
When should the initial examination of a foal occur?
when they are a few hours old
What should be examined in the initial examination?
Visually evaluate general condition, strength, mental status, ability to nurse. Observe for normal urination and defecation. Watch the foal walk and observe conformation. Auscultate the heart and lungs, and check for fractured ribs. Palpate the umbilicus. Check the mucous membrane color and CRT. Examine eyes, mouth, etc. Check for a patent rectum and umbilical hernia. If it has been greater than 12 hours, do a post-suckle check for IgG.
What is the normal TPR of a foal?
Temperature: 99-102 F
Pulse: 80-130 beats/minute
Respiratory: 60-80 breaths/minute
How should the mucous membranes and CRT be in a foal?
The mm should be moist and pink, and the CRT should be 1 second long
What should the colostrum look like?
thick yellow-orange
What should the specific gravity be for colostrum?
> 1.060 or 23% on Brix refractometer
If the colostrum is of poor quality, what should the foal be supplemented with?
banked colostrum
What should you do if there is extra colostrum?
Milk the mare and bank colostrum in the freezer - it can be stored for up to 12 months
Give me some tips for nursing.
Avoid steering the foal to the udder - give it time to explore for 2 hours
You may need to help the foals find the nipple and/or tranquilize the mare
Milk some colostrum on to your fingers and put into the foal’s mouth to encourage nursing behavior and then move your fingers to the teat
When should an enema be performed on a foal?
If it has been greater than four hours without meconium passage or straining is observed
