Lesson 31 - Neonatal Equine & Foal Medicine

What breed of horse has the highest prevalence of congenital cardiac malformations?

arabians

Why are murmurs in foals that are 1-3 days of age typically benign?

need time for the foramen ovale and ductus arteriosus to close

What is the pulse for a foal?

60-80 bpm

What considerations do you need to think about when taking a foals pulse?

1. excitement level

2. size of foal

When are arrhythmias common in foals?

less than one hours of life

How long are murmurs common?

three days

What might be causing a continuous left sided murmur?

Patent ductus arteriosus

What is the most likely etiology for a murmur on the right side of a 12-hour-old foal?

ventricular septal defect

What is the respiratory rate for a foal?

30-40 bpm but 60-80 in hotter environments

Why is auscultation of the lungs not reliable in foals?

lung sounds are very loud due to not much being present between stethoscope and lungs

How long is it normal to hear crackles in foals?

first hour of life

What do you need to palpate for when a foal is born that is related to the respiratory system?

potential rib fractures

What are clinical signs of fractured ribs in foals?

1. don't want to lie down

2. tachypnea

3. cyanosis

How do we diagnose fractured ribs?

1. palpation

2. ultrasound

3. chest radiographs

How do we treat fractured ribs in foals?

1. address respiratory issues

2. conservative if possible like stall rest

3. surgical if severe

What is the first stool passed?

meconium

How do foals help populate their hindgut microflora?

coprophagy of moms stool

Is abdominal distension normal in foals?

no; think GI or urogenital

What are the most common causes of colic in foals?

1. meconium impaction

2. ulcers

What can we use to help meconium impaction?

enemas

What type of enema do we use?

warm soapy water

How old is a neonate?

How old is a weanling?

5-6 months

What are risk factors for foal gastric ulcers?

1. hypoxemia

2. NSAID use

3. stress

4. hospitalization

What age typically gets glandular ulcers?

neonates

What age typically gets squamous ulcers?

weanlings

What are the clinical signs of foal gastric ulcers?

1. bruxism

2. ptyalism

3. intermittent colic

4. intermittent nursing

5. often subclinical

How do we treat ulcers in foals?

sucralfate PO every 2-4 hours

What is another treatment we can use in weanlings for ulcers?

omeprazole

What is the effect of sucralfate?

1. coats the ulcer

2. increases blood flow which increases prostaglanding production

What typically causes glandular ulcers?

blood flow problem

How do we definitively diagnose ulcers in foals?

gastroscopy

When is foal heat diarrhea?

10-14 days old

What is the outcome of foal heat diarrhea?

self limiting, not sick

What if you see a foal that is 10 days old with diarrhea, but is also lethargic and has a fever?

less likely to be foal heat, and more likely to be infectious

What causes bacterial foal diarrhea?

result of sepsis

What type of bacteria cause diarrhea in foals?

Clostridium perfringens or difficile

What type of diarrhea is seen with C. perfringens?

hemorrhagic

When does bacterial diarrhea occur?

How do you diagnose bacterial diarrhea in foals?

fecal toxin assay

What is a viral cause of diarrhea in foals?

rotavirus

What age does viral diarrhea occur?

How do we diagnose viral diarrhea?

1. fecal PCR

2. latex agglutination

3. ELISA

What parasite can cause diarrhea in foals?

Strongyloides westeri (threadworm)

How do you prevent parasitic diarrhea in foals?

deworming dam at birth of foal

What causes lethal white syndrome?

breeding two overo horses

What is the result of lethal white syndrome?

intestinal aganglionosis causing colic and death soon after birth

What breeds can we test for carrying lethal white overo?

1. paint horse

2. quarter horse

3. miniature horse

4. thoroughbred

What are the chances of a mare (N/O) and stallion (N/O) producing a lethal white foal?

25%

What are the chances of a mare (N/O) and stallion (N/O) producing the overo coat pattern?

50%

When do foals have their first urination?

may take as long as 10 hours; colts urinate earlier than fillies

How much urine do foals produce in a day?

150 ml/kg/day

What is the typical USG of foals?

Why is a foals urine USG low?

1. mare's milk is dilute

2. concentrating ability of the kidney is not matured

What is a great way of determining if a foal is drinking enough?

refractometer evaluation of urine (USG)

When attending a 1-hour-old foal, what might be a good use for a refractometer?

IgG status of the colostrum

What do you want to feel for on abdominal palpation?

1. inguinal and scrotal hernia

2. umbilical hernia

How do we determine whether or not an umbilical hernia will close on its own?

based on size

What do we need to do with the umbilicus?

dip with diluted chlorhexidine or very dilute betadine

What should the umbilicus never look like?

wet, swollen, hot, or painful

What are some methods of umbilical hernias?

1. surgical

2. banding but ensure not GIT contents inside

3. pressure wraps

4. pushing it back inside and it close on its own

What are signs that an umbilical hernia may need surgical correction?

1. >5cm

2. colic signs

3. not reducing on its own

What do we need to do on musculoskeletal palpation?

palpate all joints!!

What do we think of when we see a swollen joint on a foal?

septic joint until proven otherwise

How do we treat contractual deformities?

1. most resolve on their own

2. splint, oxytetracycline, flunixin meglumine

What do we check before splinting and treating a contractual deformity in a foal and why?

creatinine to determine if foal is well hydrated and kidneys are functioning well before we sedate and give NSAIDs

Why do we give oxytetracycline for contractual deformities?

binds calcium to prevent muscle contractions

How do we treat laxity deformities in foals?

1. usually improve over 3-4 days

2. exercise helps

3. wrap if needed

4. special shoes

You see a foal with a special shoe that has a back extension to it. What deformity is that supposed to help with?

laxity

You see a foal with a special shoe that has a front extension to it. What deformity is that supposed to help with?

contracture

What are the congenital/genetic diseases for friesian horses?

hydrocephalus

What are the congenital/genetic diseases for arabian horses?

1. occipito-atlanto-axial malformation

2. cerebellar abiotrophy

3. epilepsy (lavender foal syndrome, coat color dilution lethal)

What are the signs cerebellar abiotrophy?

ataxia, intention tremors, truncal sway

What causes lavender foal syndrome?

mutation in the MYO5A gene

What are the signs of lavender foal syndrome?

ataxia, muscle weakness, inability to stand or nurse and death within 72 hours

What bloodlines show the highest carrier rates for lavender foal syndrome?

egyptian arabian bloodlines

What is the best prevention for lavender foal syndrome?

genetic screening and selective breeding

What diagnostics can you perform for foal colic?

1. abdominocentesis

2. pass nasogastric tube

3. no rectal exams but ultrasound is easy

4. radiographs

What do you need to be careful of with abdominocentesis?

prone to developing adhesions

What colic treatment do you typically not want to do for foals?

feed restriction

What are some colic differentials for neonates?

1. stomach ulcers

2. uroperitoneum

3. meconium impaction

What are foal colic differentials for older foals involving the small intestine and non-strangulating obstruction?

1. ascarid impaction

2. adhesions

3. intussusceptions

4. foreign body

What are foal colic differentials for older foals involving the small intestine and strangulating obstruction?

1. volvulus

2. intussusceptions

3. hernia

What are foal colic differentials for older foals involving the large intestine and non-strangulating obstructions?

1. meconium impaction

2. trichobezoar

3. congenital malformation

4. gas colic

What are foal colic differentials for older foals involving the large intestine and strangulating obstructions?

torsion (rare)

What are inflammatory foal colic differentials?

1. enteritis

2. bacterial

3. viral

4. lactose intolerance

How do we treat foal colic?

1. enemas

2. fluids

3. surgery if needed

What cause of colic do we use enemas to treat?

meconium impaction

What type of enemas can we use?

1. warm soapy water

2. acetylcysteine if water doesn't work

What causes uroperitoneum in foals?

1. tearing of the bladder or urachus during parturition

2. prolonged recumbency while being treated for a neonatal illness

3. rupture of the urachus secondary to umbilical abscessation

4. ureteral tears are uncommon

What gender typically has a higher risk of uroperitoneum and why?

males because narrow pelvis and longer, narrower urethra

Where do most bladder tears occur in foals?

dorsum of the bladder

What can predispose foals to postnatal bladder rupture?

1. prematurity

2. neonatal encephalopathy

3. prolonged recumbency

4. cystitis

5. ascending infection

6. abdominal trauma

7. sepsis

A foal appears normal at birth but over the next 24-48 hours becomes progressively lethargic, tachycardic, and tachypneic. The abdomen becomes distended and the foal is observed attempting to urinate but is only able to produce small amounts of urine. What is the most likely diagnosis?

ruptured bladder

What physical exam parameters might you see if a foal is not nursing?

1. tacky mucous membranes

2. prolonged CRT

3. jugular fill delayed

4. decreased borborygmi

How much do we feed a foal?

start at 10-20% of body weight feeding every 2 hours with a goal of 20-30%

What are the risks of tube feeding?

1. aspiration

2. ileus

3. diarrhea

4. aerophagia

What is more reliable for determining if a foal is septic?

sepsis score sheet

What does a score of 12+ mean for sepsis?

predicts sepsis 93% of the time

What does a score of 11 mean for sepsis?

88% prediction of sepsis