Table 5.
Frequency of pathologic process detection in pathogen-positive animals for each microbiologic agent based on histopathologic score cut-offs of > 0, > 1, or > 2 in a study of the microbiological and histopathological findings in cases of fatal bovine respiratory disease of feedlot cattle in western Canada
| Microbiologic agent
|
|||||||
|---|---|---|---|---|---|---|---|
| Pathologic process | IBRV (n = 7) | BVDV (n = 26) | PI3V (n = 1) | BRSV (n = 9) | MB (n = 59) | MH (n = 68) | HS (n = 15) |
| Histopathologic score > 0 | |||||||
| Suppurative bronchopneumonia | 57% | 69% | 0% | 60% | 78% | 68% | 100% |
| Chronic suppurative pneumonia | 14% | 8% | 0% | 0% | 17% | 4% | 27% |
| Bronchiectasis | 29% | 19% | 100% | 10% | 37% | 18% | 33% |
| Fibrinonecrotizing pneumonia | 100% | 96% | 100% | 80% | 86% | 99% | 87% |
| Fibrinous pleuritis | 100% | 100% | 100% | 90% | 97% | 100% | 93% |
| Hemorrhage | 100% | 96% | 100% | 80% | 93% | 99% | 93% |
| Bronchiolar necrosis | 29% | 23% | 0% | 10% | 17% | 15% | 7% |
| Bronchiolitis obliterans | 0% | 8% | 0% | 20% | 19% | 6% | 33% |
| Acute/subacute interstitial pneumonia | 57% | 88% | 100% | 90% | 86% | 88% | 80% |
| Proliferative interstitial pneumonia | 0% | 4% | 0% | 0% | 3% | 1% | 7% |
| Other lesions | 14% | 27% | 100% | 20% | 25% | 26% | 27% |
| Histopathologic score > 1 | |||||||
| Suppurative bronchopneumonia | 29% | 23% | 0% | 50% | 53% | 35% | 100% |
| Chronic suppurative pneumonia | 14% | 0% | 0% | 0% | 8% | 0% | 20% |
| Bronchiectasis | 14% | 12% | 100% | 0% | 22% | 10% | 13% |
| Fibrinonecrotizing pneumonia | 100% | 88% | 100% | 80% | 80% | 94% | 67% |
| Fibrinous pleuritis | 100% | 92% | 100% | 90% | 92% | 97% | 93% |
| Hemorrhage | 100% | 88% | 100% | 80% | 81% | 91% | 87% |
| Bronchiolar necrosis | 14% | 23% | 0% | 10% | 12% | 13% | 0% |
| Bronchiolitis obliterans | 0% | 0% | 0% | 10% | 12% | 0% | 27% |
| Acute/subacute interstitial pneumonia | 57% | 85% | 100% | 60% | 81% | 81% | 67% |
| Proliferative interstitial pneumonia | 0% | 4% | 0% | 0% | 2% | 1% | 0% |
| Other lesions | 14% | 12% | 100% | 10% | 8% | 10% | 7% |
| Histopathologic score > 2 | |||||||
| Suppurative bronchopneumonia | 14% | 19% | 0% | 40% | 37% | 19% | 93% |
| Chronic suppurative pneumonia | 0% | 0% | 0% | 0% | 3% | 0% | 13% |
| Bronchiectasis | 14% | 12% | 100% | 0% | 19% | 7% | 13% |
| Fibrinonecrotizing pneumonia | 100% | 81% | 100% | 80% | 69% | 90% | 47% |
| Fibrinous pleuritis | 100% | 92% | 100% | 90% | 85% | 97% | 73% |
| Hemorrhage | 43% | 58% | 100% | 50% | 46% | 49% | 60% |
| Bronchiolar necrosis | 0% | 15% | 0% | 0% | 7% | 9% | 0% |
| Bronchiolitis obliterans | 0% | 0% | 0% | 10% | 7% | 0% | 13% |
| Acute/subacute interstitial pneumonia | 57% | 85% | 100% | 50% | 78% | 72% | 67% |
| Proliferative interstitial pneumonia | 0% | 4% | 0% | 0% | 2% | 1% | 0% |
| Other lesions | 0% | 4% | 0% | 0% | 3% | 3% | 0% |