Infection Route | Age of Bird | Wild-Type Virus | Embryo-Adapted Virus |
---|---|---|---|
In ovo/vertical | Embryo | No lesions | Paralyzed |
Vertical | < 4 weeks | Neurologic signs | Will not hatch |
Oral | < 4 weeks | Neurologic signs | No signs |
4 weeks to onset of lay | No signs | No signs | |
In lay | Decrease in egg production | No signs | |
Any age, bursectomized or immunocompromised | Neurologic signs | No signs | |
Intradermal (wing web) | < 4 weeks | No signs | Neurologic signs |
4 weeks to onset of lay | No signs | Neurologic signs | |
In lay | Decrease in egg production | Neurologic signs | |
Any age, bursectomized or immunocompromised | Neurologic signs | Neurologic signs | |
Intramuscular | Any age | Neurologic signs | Neurologic signs |