Avibacterium paragallinarum

Avibacterium paragallinarum (previously known as Haemophilus paragallinarum) is a capsulated, rod-shaped, Gram-negative non-motile bacteria. There are 3 serotypes of A. paragallinarum: A, B and C, which becomes important if you decide to vaccinate.

A. paragallinarum is the etiological agent of infectious coryza, an acute disease of the upper respiratory tract affecting chickens worldwide. It is spread mainly by infected chickens or chickens who have recovered from it and under great stress. The organism can spread via inhalation from aerosols or be ingested from contaminated feed or water.

A. paragallinarum is not a particularly resistant bacterium. It is destroyed by common household disinfectants, desiccation, and direct exposure to sunlight.


  • Order: Pasteurellales
  • Family: Pasteurellaceae
  • Genus: Avibacterium


  • chickens