Enteric colibacillosis

Enterotoxigenic E. ColiAetiology: 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 severityPeracute: 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