Causative agent
- Escherichia coli
- Most common serotype : O139 : K82, O141 : K85
(endotoxin-producing strain)
Differential diagnosis
- Pseudorabies
- Hemagglutinating encephalomyelitis virus infection
(HEV)
- Polioencephalomyelitis
- Water deprivation (salt poisoning)
- Teschen-Talfan disease
- Porcine stress syndrome
- Mulberry heart disease
- Chemical poisonings (arsenic, lead, mercury various
insecticides and rodenticides)
1. History taking
- Day to 2 weeks after early weaning
- Affected pigs are often the fastest growing
individual of a group
- Commonly seen under conditions of excellent
management and nutrition
- Sporadic outbreaks, not appear to spread from
herd to herd
- Mortality rate about 65% or more
2. Clinical examination
- One or more pigs may be found sudden dead
unexpectedly
- Nervous disturbance including staggering, dull,
blindness, dyspnea, stumbling and falling,
assuming a dog sitting position
- Absence of high fever
- Swollen and edema in eyelids and abdomen
- Death normally ensues within 4-48 hr after the
onset of clinical signs
3. Necropsy
- Subcutaneous edema throughout the body
- Edema in eyelids, conjunctiva, forehead, greater
curvature of stomach
- Jelly like edema in larynx, mesocolon and kidney
capsule
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- Renal cortical ischemia
- Hydropericardium hydrothorax, ascites
4. Histopathological observation
- Edema in stomach wall, lymph nodes and brain
- Small blood vessel degeneration and bilateral
leukoencephalomalacia in midbrain and brain stem
- Hyaline degeneration and fibrinoid necrosis in
arteries and arterioles
5. Bacterial isolation
Specimen : visceral organs, small intestine
Medium : blood agar ; MacConkey agar
- Isolation and identification: isolation of above
serotypes of E. coli from small intestine may be
confirmatory, E. coli levels reached 4x107 CFU/ml in
the mid jejunum and the organisms clustered and
adhered to the villi of epithelium
6. Toxin genes detection
- PCR technique
7. Serotyping
- At least 5 colonies, from jejunum, ileum or organs
- Using heated broth culture of well isolated colony
for O antigens
- Detection of O and K antigens
- Slide or tube agglutination tests with antiserum
prepared from enteropathogenic E. coli serotype
causing edema disease
Control
- Affected pigs rarely recover
- Antibiotic therapy (TC, SM, ABPC) in drinking water
- Reduction of blood pressure in clinical affected
animals
- Use of saline purgative and/or reduction of feed
intake
- Prevention of the growth of E. coli population in
the gut
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