Coryza Disease

Best 7 Advice on Infectious Coryza Disease in Chicken

Infectious coryza is a well known and commonly encountered upper respiratory tract disease of chickens that is caused by the bacterium Haemophilus paragallinarum.

Characteristics of infectious coryza in chicken

Infections Coryza is usually acute and sometimes chronic, highly infectious disease of chickens, occasionally pheasants and guinea-fowl. Infectious Coryza is characterised by catarrhal inflammation of the upper respiratory tract, especially nasal and sinus mucosae.

Infectious Coryza is caused by the bacterium Haemophilus paragallinarum and is seen in many countries especially in multi-age farms that are never depopulated. Morbidity is high but mortality low if uncomplicated, although it may be up to 20%.

The route of infection is conjunctival or nasal with an incubation period of 1-3 days followed by rapid onset of the disease over a 2-3 day period with the whole flock affected within 10 days. This results in increased culling. Carriers are important with transmission via exudates and by direct contact. It is not egg-transmitted.

The bacterium survives 2-3 days outside the bird but is easily killed by heat, drying and disinfectants. Intercurrent respiratory viral and bacterial infections are predisposing factors.

It is a usually acute, sometimes chronic, highly infectious disease of chickens, occasionally pheasants and guinea-fowl, characterized by catarrhal inflammation of the upper respiratory tract, especially nasal and sinus mucosae.
Infectious coryza is a serious bacterial disease of chickens which affects respiratory system and it is manifested by inflammation of the area below the eyenasal discharge and sneezing.[1][2] The disease is found all over the world causing high economic losses. Economic loss is due to stumping off and reduction of egg production in case of laying chickens. The disease was discovered early 1930s by considering clinical signs.[1]

Causes and Transmission

Chronically ill or healthy carrier birds are the reservoir of infection. Chickens of all ages are susceptible, but susceptibility increases with age. The incubation period is 1–3 days, and the disease duration is usually 2–3 wk. Under field conditions, the duration may be longer in the presence of concurrent diseases.
Infected flocks are a constant threat to uninfected flocks. Transmission is by direct contact, airborne droplets, and contamination of drinking water. Management has essentially eradicated infectious coryza from many commercial poultry establishments. Commercial farms that have multiple-age flocks tend to perpetuate the disease. Egg transmission does not occur

Signs and symptoms

In acute cases, lesions may be limited to the infraorbital sinuses. There is a copious, tenacious, grayish, semifluid exudate. As the disease becomes chronic or other pathogens become involved, the sinus exudate may become consolidated and turn yellowish. Other lesions may include conjunctivitis, tracheitis, bronchitis, and airsacculitis, particularly if other pathogens are involved
  • Facial swelling.
  • Purulent ocular and nasal discharge.
  • Swollen wattles.
  • Sneezing.
  • Dyspnoea.
  • Loss in condition.
  • Drop in egg production of 10-40%.
  • Inappetance.

Post-mortem lesions

  • Catarrhal inflammation of nasal passages and sinuses.
  • Conjunctivitis.
  • Eye-lid adherence.
  • Caseous material in conjunctiva/sinus.
  • Tracheitis.


A presumptive diagnosis may be made on signs, lesions, identification of the bacteria in a Gram-stained smear from sinus. Confirmation is by isolation and identification – requires X (Haematin) and V (NAD) factors, preferably in raised CO2 such as a candle jar. Serology: HI, DID, agglutination and IF have all been used but are not routine.

Differentiate from Mycoplasmosis, respiratory viruses, chronic or localised pasteurellosis and vitamin A deficiency.


Sulphonamides, tylosin, erythromycin. Flouroquinolones should be used as directed by the manufacturer.


Prevention is the most effective method of control. Farms with good vaccination and isolation methods are the best way to avoid infectious coryza. Infected birds should be separated and treated. Erythromycin and oxytetracycline are usually beneficial. sulfonamides, sulfonamide-trimethoprim, and other combinations have been successful.

More Tips of Poultry Disease

Factors Contributing to Disease in poultry

Factors that can contribute to disease include management, environment and the chickens themselves.
  • Management
  • Poor-quality food and water
  • Poor hygiene and inadequate cleaning programme
  • Leaking water bowls
  • Rat and fly problems
  • Overcrowding of chicks
  • Chickens of mixed ages reared together
  • No security measures to prevent people and animals from entering the chicken house.
  • Environment
  • Too hot or too cold conditions
  • Wet litter
  • Dusty bedding
  • High build up of chicken droppings
  • No air circulation
  • Sharp wires in the cages
  • Chickens
  • Young chickens
  • Weak second-grade chickens
  • Chickens affected with other diseases
  • Poor condition as a result of underfeeding
  • No vaccination


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