14/02/2026
Infectious coryza is a contagious respiratory disease of chickens caused by the bacterium Avibacterium paragallinarum. It spreads quickly in poultry flocks, especially in layers and breeders.
đ Clinical Signs of Infectious Coryza
Affected birds usually show:
Swelling of the face (especially around the eyes and wattles)
Nasal discharge (thick, sticky, sometimes foul-smelling)
Sneezing and coughing
Watery eyes (lacrimation)
Closed or swollen eyes
Difficulty breathing (in severe cases)
Drop in egg production (can reduce by 10â40%)
Reduced feed intake
Depression and ruffled feathers
đ Mortality is usually low, but production losses can be high.
đĄ Prevention of Infectious Coryza
1. Good Biosecurity
Restrict visitors to the poultry house
Disinfect equipment and footwear
Isolate new birds for at least 2 weeks (quarantine)
Avoid mixing birds of different ages
2. Vaccination
Use infectious coryza vaccines in endemic areas
Vaccinate pullets before they start laying
Follow manufacturerâs schedule strictly
3. Proper Housing & Management
Ensure good ventilation
Avoid overcrowding
Keep litter dry
Reduce stress (poor nutrition, sudden weather change)
4. Early Treatment
Antibiotics (e.g., erythromycin, oxytetracycline) may reduce symptoms but do not completely eliminate the infection
Always consult a veterinarian before treatment
Since youâve previously asked about poultry microbes and feed formulation, maintaining strong immunity through good nutrition (balanced protein, vitamins A & E, and minerals) will also help reduce disease impact.
