Foal diseases and disorders

Dr. Kirsty Gallacher BVMS DipACT

§ DELIVERY OF A LIVE FOAL – Breathe an initial sigh of relief!!!§ A foal can be regarded as “low risk”

§ Gestation normal duration – average 336-342 (320-360d)

§ Normal birth § Active labour (stage 2) lasts <20 mins§ No manipulation of foal is necessary

§ Normal postpartum events:§ Foal stands within 1-2 hours of delivery§ Foal nurses within 2-3 hours of delivery

§ Placenta visually normal and correct weight

1st stage labour(mins)

2nd stage ACTIVE labour (mins)

3rd stage labour –PASS PLACENTA (hrs)

<240 10-20 0.5 -3

>240 20-30 3-6

>240 >30 >6

Ifthedeliveryislongstanding:Foaldevelopsasphyxia->compromised->death

Sitting in sternal (mins)

Suck reflex (mins)

Time to stand(hrs)

Time to suck (hrs)

5 5-10 0-1 0-2

5-10 10-15 1-2 3-4

>10 >15 >2 >4

1-2-3ruleStand<1h– Nurse<2h- Passmeconium<3h

• Firstbreathswithin30seconds ofchestbeingdelivered.Initiallyfoalmayappeartogaspbutthenbreathingshouldbecomefastanddeep.

• Headshakingandsternalrecumbency with“rightingreflex”within2to3minutes.

• Strongblinkingreflexes.Mayshowvocalisation.Theheadbobsupanddownmarkedly.

• Foalstartstostruggleoftenbreakingtheumbilicalcord(atalengthof3to5cms).Averagetime6to8minutes

• Suckingreflexwithlipsandmouthwithin30minutes• Firstattemptstostandwithin30minutes• Standingsuccessfullywithin60minutes (ifnotby120minutes–call)

NORMAL FOAL

• Udderseeking• Firsteffectivesucklingwithin120min (ifnotby240min– callVET)

• Frequencyofnursing

• 7times/hr duringweek1• 3times/hr atweek4• 1time/hr at6months

NORMAL FOAL

• Afterapprox.60min newbornfoalwillliedownagain,especiallyafterfeeding

• Foalsspend33%oftheirtimelyingdown

• Ifwokenthenewbornfoalshouldbealert

• Anormalfoalwillgetupandnurseifwoken

Normal foal behaviour

• Mostfoalsnursetwiceby2½hoursofage• Sleepby1½-4hoursofage(mean3hours)• First“play”by2hoursofage• Gallopingobservedby6hoursofage• Foalstypicallyspend94-99%oftheirtimeinthefirst2weekswithin5metres oftheirdam

WHAT TO EXPECT FROM THE NEWBORN FOAL

• Thenewbornfoalispoorlycoordinated• Thejointsandligamentsmaybenotablyslack• Insomecasestheflexortendonsmaybetight• Mostoftheseproblemsself-rectifyinthefirstfewdays

WHAT TO EXPECT FROM THE NEWBORN FOAL

• Iftheproblemisnotimprovingafterseveraldaysorappearstobegettingworse– call!

• Beawareofthesevereangularlimbdeformitiesassociatedwiththeprematurefoal

§Mucous membrane colour should be salmon pink

§Capillary Refill Time < 2 seconds.

§ PARAMETERS CHANGE QUICKLY OVER TIME!!

§ HR = 40-80 bpm immediately after birth§ Will rise to 130-150 BPM within minutes of birth§ Then gradually decrease to 60-120 over the 1st week of life§ Can be normal to hear murmurs in 1st week of life (closure of

ductus arteriosus)

§ RR > 60 BPM immediately after birth§ Falls to 20-40 within 1-2 hours

§ Temperature – 37.1 – 38.9 C

§ Mucous membranes = pale pink and moist CRT<2 secs

§ Mouth – mucous membranes, palate, bite size

§ Eyes – eyelash position

§ Heart rate, murmurs, arrhythmias

§ RR, Listen to chest & palpate ribs

§ Umbilicus – dry/small, hernia, patent urachus

§ Testicles – palpate/ scrotal hernia

§ Temperature

§ Palpate joints

§ Look at legs, tendons – contracted/relaxed, ALD

§ Nursing behaviour/mares udder

§ Normal foals - spontaneous breathing and movement within secs of birth§ Great – leave to bond with mare§ If not, then rapid assessment and immediate intervention is necessary§ Place in sternal recumbency§ Remove any membranes § Bulb syringe to clear nasal passages§ Palpate/auscultate heart rate

§ Normal foals >60BPM (80-100BPM)§ <60BPM concerning

§ Vigorous rubbing & drying of the head neck & body – stimulate breathing and correct mild bradycardia

§ Stimulate the inner ears or nasal passages

§ Foal failure to transition from Fetal -> neonatal physiology

§ Foal born alive (i.e., with Heart Beat & pulse) but fails to spontaneously breathe

§ Without intervention -> hypoxia induced bradycardia> asystole & death

§ Decisions & interventions need to be made within the first 2minutes –ideally 30 secs of life

§ Foals not breathing or with HR <50 should receive ventilation

§ Ideal ventilation is with intubation

§ Next best is ventilation via a mask

§ Next best is mouth to nose

§ 10 breaths/minute – they should be quick – enough to expand the chest

§ The foal should be reassessed 30-60 secs after starting ventilation

§ Worsening bradycardia or HR<40 should initiate thoracic compressions

§ Palpate for rib fractures before starting compressions -fracture side down

§ Compressions rate = 100-120 per minute

§ If foal has cardiac arrest > thoracic compressions straight away

§ If more than 1 person then 1 can assist cardiac support and the other ventilate§ 100-120 compressions/min & 10 breaths

§ If on your own 30 compressions followed by 2 quick breaths§ Ratio 30:2 then repeat

§ Mouth to nose occlude lower nostril & oesophagus

§ Reassess after 2 minutes (take no more than 10 secs to assess)

§When spontaneous breathing >16 breaths per minute

§Heart rate >60

§ If no response after 15 minutes – stop (IF NO HEART BEAT)

Maternal risk factors

§ Difficult birth (dystocia)§ Red bag delivery (premature

placental separation)§ Premature delivery <320days§ Infection of placenta (placentitis)

§ Mare may “bag up” early, run milk, have vaginal discharge

§ Previous history of birthing/foaling problems

Foal risk factors

§ Twins§ Premature/dysmature§ Death of dam§ Meconium staining§ Foals that don’t rise and nurse by

3 hours§ Failure of passive transfer

§ Premature <320 days

§ Dysmature may have normal gestation length but signs & behaviour consistent with prematurity.

§ Unreadiness for birth§ Small size for breed – low birth weight§ Weakness, slow to stand, poor suckle reflex, laxity of flexor tendons§ Poor maternal recognition & environmental awareness§ Incomplete ossification of tarsal/carpal joints§ Fine silky hair coat, curled ears§ Synechium – “slipper hooves”

§ Muscle weakness (delayed nursing)

§ Weak suckle

§ Poor thermoregulation & glucose dysregulation

§ GI & renal immaturity

§ Entropion

§ Poor glycogen stores

§ Neonate should be gaining 0.5-1 kg per day

§ Drink ~20% of their BW on milk/day

§ Colostrum intake within 6 h of age is essential

§ Examine ability to swallow § Suckling for a long time doesn’t mean swallowing

§ Presence of milk on nostrils:

§ Pharyngeal dysfunction

§ Cleft palate

§ Other causes of dysphagia

§ Foals are born fully functional but have a naive immune system – No immediate protection

§ Colostrum provides that immediate protection § Failure of passive transfer (FPT) of immunoglobulins (Ig) is a huge

risk factor for neonatal disease § FPT due to

– Premature lactation– Failure to nurse– Poor quality colostrum

§ Evaluation colostrum quality: § Visual inspection § Colostrometer: difficult, not very accurate

– measures specific gravity– s.g. of >1.060 corresponds to IgG of >3000 mg/dl

§ Ideally check foals blood between 12-24 hours via blood test§ >800mg/dl is a pass§ >400 <800 – partial failure§ <400 – failure of passive transfer

§ By 18-20 hours the ability of the intestine to absorb ingested colostrum is almost zero

§ 12-18 hours – oral colostrum or plasma

§ >24 hours - Corrective measure – IV plasma

§ Urinate by 8 hours – full flow rather than dribbling

§ Umbilicus palpate – gloved hand§ Enlargement, heat, swelling, discharge –

ultrasound exam required§ Urachus may remain patent for first 1-2 days –

check for sepsis/infection

§ WHAT IS MECONIUM?First faecal material produced by a newborn foal§ Made up of intestinal secretrions, cellular debris, amniotic fluid

§ Clinical signs:

§ Abdominal distention and colic:

• Swishing tail, depressed, dorsal recumbency, straining

§ Digital rectal exam, ultrasound, radiographs

§ Enema

§ Warm soapy water

§ Fleet (phosphorus) enema

§ N-acetylcysteine

§ Pain control (NSAIDs)

§ Surgery, if not responsive to therapy

§ Examine oral cavity – cleft palate, bite defects

§ Observe nursing behaviour and swallowing

§ Milk at nostrils could be cleft palate or pharyngeal paralysis

§ Meconium staining

§ Passage of meconium – quantity & colour

§ Check anus – atresia ani

§ Foals are notably intolerant of abdominal pain & will demonstrate signs of severe colic

§ Hypoxic-Ischaemic Encephalopathy, Perinatal Asphyxia, or “Dummy foal”

§ Placentitis, prematurity or postmaturity, “red bag”, and dystocia

§ Some foals look normal after birth

§ Variable signs: from hyperresponsiveness to unresponsiveness:

• Poor suckle reflex, no interest on mare, dull, wandering, facial spasms, lip curling, ataxia, semi-coma or coma etc.

• Seizure-like activity can be present

§ Diagnosis is by clinical signs and elimination of other diseases (sepsis, etc.)

§ Prognosis depends on the amount of cellular damage

§ Recovery is possible with supportive care

§Foal inherits a blood type different than the mare

§1st foal usually doesn’t display any signs

§2nd foal drinks colostrum that contains antibodies against its own blood type

§ Foal consumes colostrum

§ Ab vs. foal’s RBC on surface of foal’s RBC

§ Qa & Aa blood types at risk

Signs 6-72 h after birth:

§ Dull and lethargic§ Pale yellow mucous membranes§ Tachycardia§ Cardiac murmur§ Dark yellow urine

Stallion Aa+ Mare Aa -X

Y

Y

YYY

Y

Y

Y

Y

Foal

Mare CirculationPlacenta

Anti-Aa antibody

YY

Y

Y

YY

YY

Mare circulation

Colostrum

Y

Foal Intestine

Foal Circulation

Y

Y

Y

Y

Y

Y

Y

§Screen mare for anti-RBC antigens in the last 2-3 weeks of pregnancy

§Keep foal from nursing colostrum, provide another source of antibodies such as plasma

§ Different signs than adults

§ Need prompt assessment

§ Painful foal won’t nurse

§ Will die if not supported

§ Non-infectious§ Osmotic diarrhoea & lactose intolerance

§ Microflora changes (~1 week of age)§“foal heat”

§ Faeces for culture

§ Antimicrobials in some cases

§ Supportive & nutritional care

§ Fluid therapy is often required

§ Electrolyte supplementation is important