Broodmare Foaling Flashcards
Mare gestation period? Average gestation?
325-365 days
average = 345
Easy way to calculate expected foaling date
Subtract 3 weeks from date of ovulation
Indicators of impending foaling
Bagging up
Waxing
Vulva relaxed/elongated
Muscle on side of tail soften
Mare poops
What is bagging up
Increase in mammary development, fluid starts to accumulate in the udder
Can be 6 weeks before foaling
Accumulation of milk at the tip of the teats in day or two prior to foaling
waxing (closely monitor)
When before foaling will the vulva relax/elongate
Begin 2 weeks prior
Obvious directly before onset of labor
When does softening of muscles along either side of the tail occur
2-3 days before
When before foaling will the large intestine be evacuated
Hours prior
How long before foaling should the mare be introduced to the foaling environment? Why?
At least 30 days
Exposed to any potential infectious organisms, produce antibodies she can pass on to foal
Size of foaling stall
12 x 24 ft
How should foaling stall be prepared
Clean, disinfected walls
Flooring = nonslip
Straw for bedding
Why should foaling be attended
Minimize risk of complications
Fatal complications can often be avoided
Disadvantage of foaling outside
Monitoring is difficult, increased risk of complications
She runs away
What time do the majority of mares foal
Between 10pm and 4am
Length of first stage of labour? Signs of it?
1-4 hours
Behaviour changes:
Act restless, colicky
Sweat, bite at her sides
Stand stretched out/odd
Physiological changes in the mare during the first stage
Uterus begins contraction (get foal into position)
Oxytocin hormone is released
Cervix begins opening
What happens at the end of the first stage
Outer membrane of placenta (chorioallantois) ruptures to release allantoic fluid (breaking water)
Second stage of labour is…
delivery of foal
Different kinds of placenta. Which belongs to the horse?
Diffuse (horse)
Discoid (human)
Cotyledonary
Zonary
Chorioallantois AKA? Amnioallantois AKA?
Allantochorion
Allantoamnion
What is the hippomane
Out-pouch of the allantois
What happens once the allantoic fluid is released
Strong uterine contractions = amnion appears at the vulva
Forelimbs present within 5 minutes of water break
Foal delivered in under 20 mins
What tissue should appear first? Colour? What tissue should not appear first? Colour? Why?
Amnion is pale/grey/white and should appear first
Chorioallantois is red and should still be attached to provide O2 during birth
What is the amnion
Opaque membrane that covers foals forelimbs
What does the third stage of labor consist of
Passage of placenta (chorioallantois)
What continues after delivery of the foal
Uterine contractions
How long until the placenta is passed
3 hours
What is premature placental separation
Placenta separates from the wall of the uterus before allantoic fluid is released = loss of O2 for foal
Red bag
When do red bags occur
Usually during labor, but can also happen during gestation to cause abortion
How do we diagnose a red bag
Appearance of a velvety, red mass at the vulva
How do we treat a red bag
Tear through placenta, facilitate delivery of the foal before it suffocates
Is red bag serious
Fatal to foal if undetected or not corrected
Dystocia is
Mare unable to deliver foal unassisted due to factors such as abnormal positioning or abnormally large fetus
How is dystocia diagnsoed
Delivery of foal does not progress regularly following water breaking
Palpation to detect abnormal position
how to tell which legs are front/back
Front legs bend the same way
Back legs bend opposite ways
Treatment for dystocia
Vet will attempt to reposition foal
Mare may be sedated, head positioned downhill to encourage foal to move forward to allow for repositioning
Cesarean may be necessary if unsuccessful
Is dystocia serious
Life threatening to mare and foal
Cesarean rarely results in live birth
Why do foals die when cesarean is needed
Cannot be done in general practice, need to go to appropriate clinic. Mares give birth quickly, chorionallantois will likely detach before can make it
Complications of dystocia
Risk of uterine infection, trauma to the uterus and birth canal
Death of foal
Failure to pass placental membranes within three hours of birth is called
Retained placenta
How can we check to see if placenta is retained
Use garden hose to fill the placenta with water, check for missing pieces
May be obvious if placenta is still hanging from vulva
Treatment of retained placenta
Administer oxytocin to mare = contractions
Lavage of the uterus with large volumes of fluid
Antibiotics/anti-inflammatories
How serious is retained placenta? Complications?
Easily managed, if unrecognized or untreated = serious consequences
Endotoxemia with laminitis
Uterine infections
Trauma and disruption to the perineum during foaling is
Perineal laceration
Classifications of perineal lacerations
First degree (only skin/outer layer of tissue)
Second degree (involves middle layer of tissue)
Third degree (can extend through all layers, penetrate the rectum)
How is perineal laceration diagnosed
Identified during physical examination
Treatment for perineal lacerations
First/second = none
Some second / third will need surgery
Delay surgery (weeks to months) to allow inflammation to die down/tissues heal
Antibiotics/anti-inflammatories
How serious is perineal laceration? Complications?
Most can heal/be repaired so mare can be bred again
Rarely, damage/contamination of uterus affected future fertility
Uterine damage
red bag aka
Premature placental separation
Placenta made of
Allantochorion + endometrium
