Causative agent
- Escherichia coli (Enterotoxigenic E. coli) Most
common serotype:
O8, O9, O20, O101
Differential diagnosis
- Bovine rotavirus infection
- Bovine coronavirus infection
- BVD - MD
- Bovine adenovirus infection
- Cryptosporidiosis and coccidiosis
- Bovine salmonellosis
1. History Taking
- High morbidity and mortality in intensive
rearing farm
- Most common outbreak in animals under 2
weeks of age
- Low level of immunoglobulin in colostrum
- Stresses are predisposing factor
2. Clinical examination
- Enteric disease: white scour, acute, severe and
persistent diarrhea with dehydration
- Enterotoxemic form: develop severe diarrhea,
the feces being full of gas bubbles and
whitish. Calves may die in a few days from
dehydration and acidosis
- Septicemic form in calves: a common sequel
of colostrum deprivation and often preceded
by diarrhea, and die later. Survived cases
exhibit polyarthritis and meningitis
3. Necropsy
- Dehydration
- Distended by yellow watery contents and gas
in intestinal tract
- Grossly distended with fluid and a milk clot
in abomasum
- Hyperemia in mesenteric lymph nodes
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4. Histopathological observation
- Villous atrophy, distraction and severe
inflammation in the intestinal epithelium
5. Bacterial isolation
Specimen : fresh carcass only, rectal swab,
contents of duodenum or jejunum
- Need quantitative culture of intestinal
contents in TS broth (fresh duodenal content
fresh rectal swab)
Medium : blood agar and MacConkey agar for
direct culture. Pathogenic E. coli is
usually  ☐-hemolytic and mucoid
type on blood agar. On MacConkey
agar, colonies 2-4 mm, red, opaque,
rough or smooth. Zone of
precipitated deep pinky color around
colonies. Identification by
biochemical characters and toxin
production
6. Serotyping and detection of pili antigen
- If necessary, try serotyping of O group antigen
and detection of pili antigen or heat stable
toxin of ETEC by PCR
Control and Prevention
- Reduce exposure of newborn calves to the
infective agents
- Provide maximum application of maternal
immunity with adequate colostrum and
improvement of animal environmental factors
- Increase specific resistance of newborn calves
by vaccination of the dam and the newborn
- Supply electrolyte and antibiotic orally
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