Equine Disease and Lameness Exam 4

What type of ovary is this

quiet functional ovary

What type of ovary is this

ovary with corpus luteum

What type of ovary is this

ovary with follicle

What is made up of many fimbriae that surround the ovary collecting the ovulated egg

infundibulum

What is the “tortuous” narrow tube that the ovulated egg travels through to get to the uterus where fertilization occurs

isthmus

What is the structure made up of the infundibulum and isthmus

oviduct

What does the junction of the isthmus and uterus allow

only fertilized eggs can enter the uterus

When does the fertilized egg make it to the cuterus

approximately 6 days after fertilization

Is the conceptus very mobile or immobile

mobile

Due to the mobility of the conceptus, what is the movement and frequent contact with the endometrium thought to aid in

maternal recognition of pregnancy

What is the inner lining of the uterus

endometrium

What does maternal recognition of pregnancy prevent

regression of the corpus luteum on the ovary - which maintains pregnancy

Why is the equine conceptus highly unusual

takes a long time to form a blood connection with the mare

How long does it take for the conceptus to form a blood connection with the mare

40 days until about 150 days to complete

What is the placental attachment to the uterine wall

epitheliochorial and diffuse

What does it mean for the placenta to have an epitheliochorial attachment

the chorion portion of the fetal membranes is in contact with the mare’s uterine lining

What does it mean for the placental attachment to the uterine wall to be diffuse

the chorion has contact with the uterine lining all over, not just in specific locations

How is pregnancy diagnosed

by hand via rectal palpation or ultrasound

When can pregnancy be diagnosed by hand

25-30 days

When can pregnancy be diagnosed by ultrasound

11-14 days

By what point does the fetus have a heartbeat

day 28

How long are mares pregnant

335-340 days (can range from 300-385)

What are reasons that gestation be longer

mare has low plane of nutrition, cooler weather, or carrying a mule

What is the act of giving birth called

parturition/foaling

What are signs of foaling within the udder

distention 2-6 weeks prior

What are signs of foaling within the muscles and ligaments

relaxation of muscles and ligaments around the pelvis 7-10 days prior

What happens in the hours prior to foaling

separation from the herd

What happens 2-4 days prior to foaling

waxing

What happens during the first stage of parturition

fetal positioning

What are symptoms of fetal positioning

abdominal discomfort, restlessness, uterine contractions

What happens during the second stage of parturition

fetal membrane rupture, contractions, birth of the foal

What is the third stage of parturition

passing of fetal membranes

How soon after parturition should fetal membranes be passed

within 3 hours

What is waxing

pre-colostrum mucous plug at the tips of the teats

What should break when the foal is born

amniotic membrane

How long can the first stage of labor last

variable - a few hours to a day

How long is the second stage of parturition

15-30 minutes after the fetal membrane ruptures

What happens shortly after the water breaks

abdominal contractions, birth of foal

What is the inflamation/infection of the placenta

placentitis

What is the way placentitis occurs, where infectious organisms travel up the reproductive tract

ascending infection

What are the clinical signs of placentitis

vaginal discharge and premature “bagging up”

What is an ascending placentitis infection sometimes due to

poor vulvar conformation

What is the cause of placentitis where bacteria circulate through the bloodstream

hematogenous

Where does placentitis occur

diffusely across the placenta or localized infection

What can placentitis lead to

detaching of the placenta or issues at parturition and can be difficult to break

How can placentitis be prevented

check routinely throughout pregnancy via ultrasound

What is the pathology where there are amorphous pieces of allantoic material often delivered along with the fetus

hippomanes

How do hippomanes form

fluid and particulates collect around a central nidus

What are hippomanes mostly comprised of

mucoproteins and calcium phosphate

What do hippomanes look like

beige-brown-green color, firm, several cm in diameter

Are hippomanes pathologic (related to disease)

no

What are the issues with twins

rarely born full term and alive, often retained membranes and a dystocia

What is recommended when finding twins

terminate one or both (can pinch one)

When should twins be terminated

35 days or less

What is the pathology where the outer fetal membranes (chorion and allantois) separate from the uterine lining before the amnion ruptures

premature chorioallantois separation “red bag”

What can premature chorioallantois separation quickly result in

foal not getting enough oxygen and dying via suffocation

Is premature chorioallantois separation an emergency

yes

What is premature chorioallantois separation caused by

placentitis, twins, fescue toxicity, or no reason at all

What is the foaling problem that does not allow the mare to give birth on her own

dystocia

Is dystocia caused by the mare or fetus

either

Why is dystocia a serious problem

often fatal for the mare and/or foal

What must be considered when assisting a mare with a dystocia

cleanliness and gentleness to prevent trauma of vulva, vagina, or uterus

Whom should dystocia be addressed by

veterinarian or experienced caretaker

What are the mare causes of dystocia

uterine atony, uterine torsion

What is the mare cause of dystocia which is failure of the uterine muscles to contract

uterine atony

What is the mare cause of dystocia where the uterus has twisted on its axis - cranial or caudal to the cervix

uterine torsion

What are the foal causes of dystocia

malposition, fetal malformation

What should be cleaned well when addressing a dystocia

external vulva and surrounding tissue with iodine and warm water

Why is cleanliness essential when addressing a dystocia

to prevent infection of the mare’s reproductive tract

What is there never too much of when addressing a dystocia

too much lubrication

What is the general rule of traction when addressing a dystocia

if traction (pulling) requires more strength than two strong men, consider alternative method

What is often required to aid in grip and traction when addressing dystocia

obstetrical chains

What are the secondary options for addressing dystocia

controlled vaginal delivery, casarean section, fetotomy

What is the way to address dystocia where the mare’s hindquarters are hoisted to push the GI tract cranially

controlled vaginal delivery

What is required for a controlled vaginal delivery

mare must be anesthetized

What is the way to address a dystocia that is delivery of the foal by an abdominal and uterine incision

cesarean section

What is the option of addressing dystocia where the fetus is cut into manageable pieces within the uterus to be delivered vaginally with assistance

fetotomy

When is a fetotomy done

when cesarian section is not an option

What must be examined after every delivery

fetal membranes

Where are the fetal membranes ruptured in a normal birth

the cervical star

What is the weakened area of the chorioallantois where the fetal membranes rupture

cervical star

What should the fetal membranes appear as

the letter F

What is included in the fetal membrane’s “letter F”

two uterine horns and the uterine body

What is the condition where missing pieces or the entirety of fetal membranes have not passed within three hours called

retained placenta

How is a retained placenta treated in early cases

oxytocin to promote uterine contractions

How is a retained placenta treated in cases over 8 hours

antibiotics and anti-inflammatories

What does a retained placenta predispose the mare to

laminitis

What is the loss of pregnancy during the first 42-50 days of pregnancy called

early embryonic death

What is the most common time to lose a fetus

during the first 42-50 days (early embryonic dreath)

What is a loss of pregnancy after 50 days of pregnancy called

abortion

What condition causes abortions, especially in the third trimester

equine herpes virus (EHV)

What type of pathogen is equine herpes virus

airborne

How is equine herpes virus transmitted

easily - shared water, nose-to-nose contact, neighboring stalls

When should a horse be vaccinated to equine herpes virus

3, 5, 7, and 9 months of pregnancy

Who should be vaccinated for equine herpes virus other than the pregnant horse

other horses in the barn

What are the symptoms of EHV-1 in the mare

no disease, can have normal placenta or edematous (thickened with intercellular fluid)

What are the EHV-1 symptoms in the fetus

fetal lesions - swelling and fluid accumulation under the skin, jaundice, enlarged liver with pale lesions, large amounts of intrathoracic fluid

What can twinning cause

abortion

When does the mare typically lose the fetus when twinning

8-9 months

What symptom will the mare usually experience when abortion due to twinning

premature lactation