Causative agent
- Most common serovars :
Salmonella typhimurium(O-4 group),
S. choleraesuis (O-6, 7 group),
S. enteritidis (O-9, 12 group) and others
Differential diagnosis
- Swine dysentery
- Campylobacter infection of swine (PHE)
- Necrotic enteritis
- TGE
1. History taking
- High morbidity and mortality in weaning piglets
- Persistent outbreak in every rearings
- Introduction of carrier pigs
- Contamination of feed and farm utensils
2. Clinical examination
- Septicemia : depression, dullness, high fever (40.5-
42°C), weakness and death
- Enteritis : persistent diarrhea, severe emaciation,
intermittent fever, dehydration, watery to pasty
yellow-whitish feces, at intervals the feces contain
spots of blood, mucous and fibrinous casts
3. Necropsy
- Dark red to purplish discoloration of the skin on the
abdomen and ears
- Subcutaneous petechial hemorrhage
- Swollen mesenteric lymph nodes and spleen
- Small and whitish necrotic foci in liver
- Turkey-egg appearance at kidney and pneumonia
- Button ulcers in ileocaecal regional membrane in
chronic cases
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4. Histopathological observation
- Reticuloendothelial hyperplasia in lymph nodes
and spleen
- Necrotic foci and typhoid nodule in liver
- Hemorrhage and necrosis in mesenteric lymph
nodes
- Petechial hemorrhages on pleura, peritoneum,
endocardium, kidney and meninges
5. Bacterial isolation
Specimen : spleen, liver, lungs, mesenteric lymph
nodes and feces
Medium : propagational and selective media with
common media (see description in avian
salmonellosis) (selenite broth toxic to S.
Choleraesuis)
- Identification : biochemical characters
6. Serotyping
- Confirmation of O-group (antigen) by slide
agglutination test
- Complete serotyping of O antigen and H antigen is
performed in NIAH
Control
- Prevent introduction of carrier animals or
contaminated feed made from animal origin
- Limit spread within a herd
- Cull infected or carrier animals
- Prevent or treat animals with antibiotics
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