Equine Reproduction, Parturition, and Foal Neonatal Care

Seasonally polyestrous

What type of estrous cycle do mares have?

21 days

How long is the average estrous cycle in mares?

4-7 days

How long is the average duration of estrus in mares?

320-370 days

What is the average gestation period for light breeds in days?

11-12 months

What is the average gestation period for light breeds in months?

Rectal ultrasound

What method is most commonly used to determine the stage of estrous in mares?

20-100 mL

What is the average semen ejaculation volume for stallions?

Breeding phantom and artificial vagina

What is most commonly used for semen collection?

113 degrees F

What is the optimal temperature inside the artificial vagina?

Yes

Is artificial insemination a sterile procedure?

Increased photoperiod

What does the natural breeding season center around?

January 1st

What is the designated birth date for all horses in the northern hemisphere?

Shortens Cl lifespan

What is the purpose of PGF2a administration?

Maintains long-term estrus suppression, suppresses LH, and blocks ovulation

What is the purpose of progesterone administration?

Developing follicles

What produces estrogen?

Elevated tail raise and winking

What are the most consistent signs of estrus?

Spring and summer

In what seasons do mares usually breed and conceive?

Ultrasound per rectum

What is the most accurate method to diagnose pregnancy?

Rectal palpation

What is the most common and rapid method used to diagnose pregnancy?

18 days

How early post ovulation can rectal palpation be used to diagnose pregnancy?

10 days

How early can ultrasound per rectum be used to detect a fetus?

Deaths abortion, or stillbirth of both fetuses

What do twin embryos usually result in?

Older, injured, subfertile, 2 years old, and in competition

What mare signalment may require embryo transfer?

30 days

How long before impending birth should mares be vaccinated and dewormed?

Thick and puffy vulva, relaxed and elongated vulva hours before parturition, visible changes in the position of the foal, and pear-shaped abdomen

What are some subtle signs of impending birth in mares?

Uterine contractions

What is the onset of stage 1 of parturition?

Water breaks

What is the end of stage 1 of parturition?

2-4 hours

How long is stage 1 of parturition?

Foal pushed toward cervix

What happens during stage 1 of parturition?

Rapture of chorioallantois

What is the onset of stage 2 of parturition?

Delivery of fetus

What is the end of stage 2 of parturition?

20-30 min

How long is stage 2 of parturition?

Soles pointing downward

What position are the forefeet of the foal in during stage 2 of parturition?

Oxytocin release, uterine contractions reinforced

What occurs during stage 2 of parturition?

Chest is through the vulva

When can the foal breathe on its own during parturition?

Delivery of fetus

What is the onset of stage 3 of parturition?

Passage of the fetal membranes

What is the end of stage 3 of parturition?

30 min to 2 hrs

How long post-foaling is the placenta expelled?

3 hrs

How long post-foaling is the placenta considered retained if not expelled?

Tip of non-pregnant horn

What is the most likely part of the placenta retained?

Oxytocin and antibiotics

What is the treatment of retained placenta?

No

Should the umbilical cord be cut?

4-5 days

How long is the neonatal period?

20 min

How long after birth should newborn foal exhibit a suckle reflex?

30-60 min

How long after birth should newborn foal stand?

60-180 min

How long after birth should newborn foal nurse?

10 hrs

How long after birth should first urination occur within?

24 hrs

How long after parturition should meconium be passed by?

Thick, sticky, yellow

What appearance does good quality colostrum have?

12 months

How long is IgG concentration stable for from drinking colostrum?

18 hrs

When are peak serum levels of IgG achieved by?

Dummy foal syndrome

What condition is a lack of oxygen causing cerebral edema, ischemia, and necrosis of the brain?

Equal to or less than 320 days

When does prematurity occur?

On a warm, well-padded surface in semi-sternal recumbency

How should critically ill neonatal foals be placed?