Foal cases

Question 1

Case 1:
2 day old foal
Unobserved birth, No problems during pregnancy
Looked fine yesterday
This morning: Flat, unable to stand

What are your differentials?

Answer 1

Hypovolaemia / dehydration +/- electrolyte abnormalities
Sepsis
Hypoxia
Hypoglycaemia
Hypothermia

Question 2

What % of BW is fluid in adults vs foals?

Answer 2

Adult: 60% H2O
Foal: 75% H2O

Question 3

What % of a foals BW should they have in milk?

Answer 3

25% bwt milk daily → 12.5 l/day → 0.52 l/h
6h → 3l → 6% DH
Assume DH if not nursed for 4-6 h

Question 4

How is hypovolaemia diagnosed?

Answer 4

1. Systemic lactate
2. Central blood pressure
3. Arterial blood pressure >60 mmHg
4. Urine production and specific gravity

Question 5

How is hypovolaemia treated?

Answer 5

Bolus method:
- 1l crystalloid i/v → re-assess
- 1-2 more boluses if necessary
- Assess urine production and mentation
- Hartmann’s

Question 6

List the causes of hypoxia in foals

Answer 6

PAS (hypoxic ischaemic encephalopathy), ARDS, PPH, respiratory disease, sepsis, hypoglycaemia, body position

Question 7

How does hypoxia present?

Answer 7

Tachypnoea, dyspnoea, mm

Question 8

How is hypoxia in foals treated?

Answer 8

Body position: sternal recumbency
Treat primary cause
Supplemental Intranasal O2 therapy (4-10l/h)
- If no improvement PaO2: consider cardiac shunt or PPH
- If persistent hypercapnia and acidosis: doxapram, caffeine, mechanical ventilation
- If persistent hypercapnia and alkalosis: compensatory: do not treat

Question 9

How is sepsis diagnosed?

Answer 9

Haematology
- Leukopaenia and neutropaenia
Biochemistry
- Helps determine primary diagnostic (liver, renal, etc)
- Hypoglycaemia: associated with sepsis
- ↑ SAA

Question 10

… predisposes to sepsis in foals?

Answer 10

Failure of passive transfer

Question 11

How are the level of immunoglobulins changed in sepsis?

Answer 11

↓IgG → suspicion of sepsis
But may also indicate problems that reduce colostrum absorption

Question 12

How is sepsis treated?

Answer 12

Control infection - antimicrobials, hyperimmune plasma
Haemodynamic support
Respiratory support
Supportive therapy

Question 13

Describe hypoglycaemia in foals

Answer 13

Impaired mobilisation of glucose in premature, septic and Perinatal asphyxia syndrome

Question 14

How is hypoglycaemia in foals managed?

Answer 14

Monitor regularly
Aim to maintain between 4-10 mg/ml
Requirement:
- 40-50 Kcal/Kg/day
- Glucose IV
- Enteral nutrition
- Parenteral nutrition

Question 15

Describe hypothermia in foals

Answer 15

• Heat is produced by shivering and nonshivering thermogenesis, which requires brown adipose tissue stores. However, in the foal there is no evidence of any brown adipose tissue stores.
• Until the foal ingests colostrum, the energy to fuel metabolism comes from endogenous sources of glycogen.
• Weak or premature foals are susceptible to hypothermia due to their poor body insulation, diminished energy reserves and poor energy intake

Question 16

How is hypothermia in foals treated?

Answer 16

Avoid cold air and drafts
Radiation heaters
Rugs
Bear hugger
Bandage distal limbs

Question 17

Jaunice is foals is due to?

Answer 17

Neonatal isoerythrolysis

Question 18

What is neonatal isoerythrolysis?

Answer 18

• Primary immune-mediated haemolytic anaemia of foals that occurs when the mare produces antibodies (alloantibodies) against a red blood cell antigen inherited from the stallion (alloantigen) that is not present in the mare
• Only affects a second foal born
• The first foals blood mixes with the maternal blood and antibodies are produced against this RBC type