Causative agent
- Clostridium perfringens type C
Differential diagnosis
- Coccidiosis
1. History taking
- Acute outbreaks with high morbidity and mortality
- Sporadic outbreaks in 4-8 weeks old broiler
chicken flocks
- Some outbreaks appear to follow or with
coccidiosis, and changes of diet
- Affected birds exhibit weakness and dysentery
- Predisposing causes of outbreaks include
overcrowding and regrouping
2. Clinical examination
- Ruffled feathers, marked depression, anorexia,
bloody feces with mucus and diarrhea, similar to
coccidiosis
- Very reluctant to move
3. Necropsy
- Lesions in the anterior distal part of the small
intestine : congestion of mucosa, desquamation of
mucosa, erosion patch, edema and congestion
- In acute stages the lumen contains hemorrhagic
exudate with epithelial debris
- The lesions are resemble to chronic Eimeria
brunetti or Eimeria maxima infection
4. Histopathological obersvation
- Villi partly or completely denuded of epithelium
- Severe hemorrhagic necrosis of the intestinal
mecosa with fibrin admixed cellular debris adherent
to the necrotic mucosa
- Large number of Gram positive rods in mucosal
epithelium
- Degeneration and necrosis of liver
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5. Duodenal contents smear
- Microscopical examination of scrapings and smears
from the changed areas of the bowel reveal large
numbers of Gram positive short and thick bacteria
singly or pairs
6. Bacterial isolation
Specimen : small intestinal contents
- Anaerobic culture on Zeissler agar or Kamamycin
yolk CW agar at 37°C for 48 hr need quantitative
culture positive as≥106 CFU/g because C. pertringens
is inhabitant in the gut of healthy animals
- Identification : small biconvex and glistening
colonies, sharp hemolytic zone
7. Experimental animal inoculation
- About 70 ml of small intestinal contents →
centrifuge 7,000-12,000 rpm for 30 min →
0.1 ml of the supernatant inject IP into 2-3 mice
→ mice will die within 24 hr due to toxemia
8. Toxin detection
- Pure cultured liquid medium → centrifuge
12,000-15,000 rpm for 30 min → inoculate
the supernatant into mice (same as above)
9. Toxin neutralization
- Need antitoxin type A-E (see necrotic enteritis of
swine, No. 53)
Control
- Water medication : penicillin, tetracycline
bacitracin, avoparcin and lincomycin with program
- Disinfection of litters, floor, wall etc
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