Infectious Bronchitis is an acute, highly contagious viral disease affecting poultry. It causes respiratory, renal, and reproductive disorders and may result in high and rapid mortality rates due to its short incubation period, which ranges from 18–36 hours. The disease course is relatively short, lasting up to 6 days; however, infected birds can remain carriers, shedding the virus via droppings and nasal secretions for up to 5 weeks post-infection.

 Modes of Transmission:

– Inhalation of virus-contaminated air by birds.

– Direct contact between infected and healthy chicks.

– Ingestion of feed or water contaminated with droppings from infected birds.

Diagnosis:

– Post-mortem findings (PM).

– Laboratory testing: PCR.

– Clinical signs:

• A Characteristic gasping with tracheal rales and upward extension of the neck.
• Increased water consumption as a result of renal dysfunction.
• Reduced feed intake.
• Birds crowding near the heat source.
• Depression with ruffled feathers.
• Mucoid nasal and ocular discharge.
• A marked decrease in egg production, with the appearance of numerous shell-less or wrinkled eggs. Shell deformities occur due to irregular calcium deposition, and Eggs often have watery albumin in a large proportion.

Prevention:

– Use of live and inactivated vaccines with appropriate matching between the vaccine strain and the circulating field strain.

– Vaccination programs should be designed according to the epidemiological status of the area and the type of birds.

 Supportive Care:

– Increase house temperature by approximately 2°C above the normal level, with enhanced ventilation to reduce ammonia concentration.

– Reduce dietary protein content by 2–3% to decrease uric acid production, thereby relieving pressure on the affected kidneys.

– Use liver and kidney tonics to support vital functions and reduce physiological stress.

– Treat with appropriate antibiotics in cases of secondary bacterial infections.

– Birds should be supplemented with essential amino acids (Methionine, Lysine & Threonine) and vitamins (A, C, E & D₃).

Dr. Ahmed Nasr Elwagih

Poultry Health & Disease Consultant