While infectious coryza has not been detected in Michigan, MDARD is aware of and monitoring cases of the disease in chickens from Ohio and Indiana. The disease is important to be aware of because the acute respiratory signs of infectious coryza could cause it to appear like highly pathogenic avian influenza (HPAI).
Infectious coryza is a respiratory disease of chickens caused by the bacterium Avibacterium paragallinarum. Clinical signs of the disease include lethargy, nasal/ocular discharge, labored breathing, coughing, and sneezing. The most prominent sign of the disease is facial edema, a swelling of the face. Unlike HPAI, infectious coryza is not a reportable animal disease in Michigan.
Fortunately, the disease does not pose a zoonotic risk or any food safety concerns regarding the meat and eggs from infected birds.
The disease can be transmitted directly from an infected bird, inhaling airborne bacteria, or ingesting contaminated feed/water. The disease incubation period is usually around 24-48 hours, so acute onset is typical.
While mortality from infectious coryza is low, morbidity and decreased egg production can be high. If secondary infections occur, mortality rates can quickly climb. Also, if an infected flock recovers, they can remain a reservoir for the disease, often asymptomatically, possibly leading to further spread of the disease within and between flocks.
Even though commercial vaccines are available in more endemic regions, vaccine suppliers may have difficulty meeting demand if a large outbreak of infectious coryza occurred in the Midwest. Therefore, some of the best strategies to prevent the disease include focusing on all-in/all-out management, comprehensive cleaning and disinfection, and enhanced biosecurity practices.
MDARD will continue to monitor the disease and provide outreach to key partners and stakeholders as needed as the situation continues to evolve in Ohio and Indiana.
If you have any questions related to infectious coryza or other poultry diseases, please contact MDARD at 800-292-3939.