Equine Reproduction Flashcards
What type of estrus cycles do horses have?
seasonally polyestrous
When is a horse first bred?
2-3 years - varies
How long is the gestation period?
360-365 days
What is the average weaning age?
4-7 months
Prolonged labor usually is _________________.
fatal to foals
What is usually done during a reproductive exam?
rectal palpation, ultrasound, visual exam of vagina and cervix, uterine culture and sometimes uterine biopsy
What is the most common cause of infertility in mares?
bacterial uterine infection
Infections are suspected in ____________.
any mare that has had repeated unsuccessful breeding or early loss of embryo
What is endometrial (uterine) biopsy?
used to evaluate fertility
What is the most commonly used method to collect sperm?
artificial vaginas
How is a stallion prepped for semen collection?
erect penis is washed with warm water, tail wrapped and buttock washed
What does “placing a mare under lights” mean?
the mare’s ovulatory season is advanced by approximately 40-60 days by maintaining mares under conditions of 16 hours of light
What would you do with a mare after artificial insemination to discourage expulsion?
walk her
How often is AI repeated in a mare?
every 24-48 hours while in heat
When does foaling occur?
80% occurs at night
What are some signs of impending parturitions?
sweating across neck and flank, “waxing”
What is “waxing”?
leaking of colostrum that dries on the teat and makes “wax-like cap”
What is stage one of the parturition cycle?
preparatory stage
How long does phase one of the parturition cycle last?
2-4 hours
What is stage two of the parturition cycle?
delivery of fetus
How long is the typical delivery of a foal?
20-30 minutes
The placenta separates _________.
rapidly
If a foal is not seen in ~20 minutes, what does that mean?
dystocia
If a foal is not fully delivered in 30-45 minutes, what does that mean?
dystocia
If a foal is not fully delivered in >60 minutes, what does that mean?
poor outcome for foal, possible death
What is phase three of the parturition cycle?
passage of fetal membrane/placenta
What does it mean if the placenta does NOT pass in 4-6 hours?
placenta is considered to be retained
What is the most common way to treat dystocia?
mutation and delivery by traction
What is the last resort to treat dystocia?
c-section
Which species has the longest gestation?
horse
What is a neonates normal HR/RR ~5 minutes after birth?
> 60bpm
When does a newborn foal first stand?
30-60 minutes after birth
When does a newborn foal start to nurse?
60-180 minutes after birth
When does a newborn foal have first bowel movement?
<24 hours after birth
What needs of newborns must be addressed?
adequacy of passive transfer of antibodies
What is the first priority after delivery?
oxygenation/pulse assessment —> ensure clear airway
Horses are _________ breathers.
obligate nasal
What is the first step in maintaining body temperature after birth?
drying off neonate
If a horse needs heat support, what temperature should be started with?
start at 100*F
How should the umbilical stump be treated?
dipped 2-3 times a day for a few weeks, monitor stump
What are some clinical signs of persistent patent urachus?
foal dribbles or streams from umbilicus
How often do foals nurse?
every 1-2 hours
What glucose can be fatal in neonates?
<40g/dL
What is meconium?
first bowel movement
What is the leading cause of colic in neonates?
impacted meconium
What is colostrum?
first milk, contains antibodies
What is passive transfer?
transfer of antibodies from mare to neonate
Why is passive transfer important?
foal’s immune system is not fully capable of producing protective antibodies until close to 8 weeks
What is the leading cause of sickness and death in first week of age?
septicemia
What is the leading cause of septicemia?
failure of passive transfer
What antibody level would suggest failure of passive transfer?
<200mg/dL
What is normal during foal’s heart auscultation?
patent duct arteriosus (PDA) is normal before 4 days of age and will go away
What is normal during foal’s lung auscultation?
moist sounds during first few hours
What are fetal hoof pads?
hooves are covered with at birth, fall off on their own
What are the two major limb deformities?
angular and flexural
What is a flexural deformity?
“dropped ankle”, determined by looking at leg from side
What is a valgus angular deformity?
feet point away from body’s median plane
What is a varus angular deformity?
feet point toward body’s median plane
What is a windswept angular deformity?
varus deviation on one leg and valgus deviation on other
How can you prevent a foal from getting sick?
check IgG levels, maintain excellent sanitization, treat the umbilicus, close monitoring of vital signs
