| 0 | No gross lesions |
| +1 | The absence of thickening caecal walls with few scattered petechiae, normal caecal content can be seen |
| +2 | Moderately thickening of caecal walls, Numerous lesions can be observed with detectable blood in the caecal content |
| +3 | Higher thickening of caecal walls, High amount of blood and caecal cores, Absence of normal caecal contents and the serosa of the unopened caeca shows the petechia on the entire surface |
| +4 | Greatly thickening of caecal walls, the caeca are distended with a large amount of blood and caecal cores combined with faecal debris, the distal end of caeca get shrunken and ruptured, dead birds also scored +4 |