Enteric colibacillosis

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Enterotoxigenic E. Coli

Aetiology:

Most common strain causing neonatal calf diarrhoea

Produces enterotoxins —> secretory diarrhoea

Bacteria attach to hosts enterocyte —> releasing enterotoxin which induces the intestinal epithelial cell to secrete fluid high in chloride ions

Water, Na, K and HCO3 ions follow chloride —> electrolyte rich fluid in intestinal lumen —> diarrhoea

Mainly in the first 14 days of life

‘White scours'

Clinical signs:

Vary in severity

Peracute:

Dehydrated

Weak

Comatose calves within hours of onset

Calves are bright with good suck reflex until develops

Large amounts of watery diarrhoea

Splashing sounds in intestine (auscultation)

Acute

Obvious, watery diarrhoea, progressive dehydration and weakness over 12-48 hours

Character and colour of faeces —> watery and yellow, white or green

Often rancid odours

Low grade pyrexia may be seen

Clinical Pathology

Peracute —> metabolic acidosis with decreased plasma bicarb and low venous pH

Hyperkalaemia and hypoglycaemia

Dehydration >8%

May see mild hypoNa and hypoCl

Treatment:

Fluids

Antibiotics

Ceftiofur 2.2mg/kg IM or SC BID

Amoxicillin 10mg/kg

3-5 days

Flunixine