Infectious Coryza In Poultry: Signs, Causes, Control And Treatment; This is a respiratory disease of chickens, and it is acute. Some of its characteristics are swelling under the eyes, sneezing and nasal discharge. The virus is global in distribution. However, it is only observed in chickens. The symptoms above can also occur in pheasants and quail, but they are caused by a different causative organism.
The disease occurs in layers and pullets mainly in countries like the USA and other developed countries. It can also occur in broilers occasionally. The disease is most common among commercial flocks in the southwest and California compared to other parts of the United States. Be that as it may, significant outbreaks had been recorded in the northeastern part of the USA. Very young chickens, as young as three weeks old, have been reported to come down with the infection in developing countries. Infectious Coryza in poultry is a common problem in developing countries due to stress, poor environment, and poor biosecurity. No public health significance had ever been registered about the diseases.
Nature of the disease
• The infection is a bacterial disease and attacks the upper respiratory tract of chickens. It is highly contagious and acute
• When it gets complicated by some other pathogens, it can culminate in a chronic respiratory disease.
• Some of the symptoms are discharges from the nostrils and eyes, facial edema or swelling of the face.
Causes Of Infectious Coryza In Poultry
• Homophiles paragallinarum is the bacteria responsible for this disease.
• The condition is more severe in older birds
• The main source of the disease is carrier birds and clinically affected birds
• The disease can be spread via airborne means over a short distance and by drinking water already contaminated by the nasal discharge of birds affected by this condition.
• Direct contact with affected birds can also occur, representing the lateral means of transmission of the diseases.
• Intercurrent infection with infectious bronchitis virus and other microorganisms are among the factors that can prolong the infection and make it more severe. Other microorganisms associated with this are Pasteurellaspp, Escherichia coli, Mycoplasma gallisepticum and Laryngotracheitis virus. Unfavourable environmental conditions are also responsible.
• A marked drop in the number eggs produced can lead to economic losses; up to 40% reduction has been recorded.
|01 Swelling and cyanosis of eyelids and face|
|02 Swelling and cyanosis of eyelids and face|
|02 Swelling and cyanosis of eyelids and face|
• Low mortality, high morbidity and rapid spread occurs in birds being given deep litter management
• Some of the typical symptoms are swelling of the face or facial edema, mucus-like discharge from the eyes and nose, and sneezing.
• Difficulty in breathing, swollen wattles and conjunctivitis with closed eyes are recorded in severe cases of the diseases.
• The reduction of egg production can lead to a reduction in water and feed consumption.
|Infraorbital sinus showing consolidated caseous exudate|
• Conjunctivae and infraorbital sinus record fibrino-purulent inflammation, as well as the nasal passage.
• There can be yellowing and consolidation of the sinus discharge as other microorganisms get involved or the disease becomes chronic.
• Patient also experiences prominent subcutaneous edema of the wattles and face
• There can be involvement of the upper trachea. Involvement of the air sacs and lungs are only recorded when there is a chronic complication of the disease.
Prevention and control
• The best way to control this disease is to prevent the infection from getting into the farm. This can be achieved via buying the birds from sources that are free from the diseases, strict biosecurity, sanitation, and hygiene.
• Recovered birds are usually sources of infection. As a result, the infection can be prevented by removing such birds and getting them culled from the rest of the flock.
• The disease can be eradicated by practicing all-in-all-out rearing system.
• The chicken can be protected from infection by giving them vaccines made from inactivated whole culture or organisms that contain adjuvant to protect the chickens from the disease.
• There is need to give the chickens two doses of vaccines in endemic areas, and each of the doses needs to contain a minimum of 108 colony-forming units. The vaccine should be given subcutaneously, with the first one given when the chickens are about 16 weeks old and the second one given when they are about two weeks old.
• The building should be rested after cleaning and disinfecting it for a minimum of one week. New birds should not be introduced until after this.
• Restocking should only be done with older and day-old chickens that are certified to be free from the H. paragallinarum infection.
Treatment Of Infectious Coryza In Poultry
Coryza is due to bacterial infection, and it can be treated using antibacterial agents. Each of the antibiotics to be used comes with container label; the instructions on the label must be followed when they are being given to the chickens. The clinical signs of the disease can be curtailed by the antibiotics. Be that as it may, they do not kill the bacteria from the birds carrying them.
Some of the antibacterial agents that can prevent the spread of the condition are erythromycin, tylosin, sulphonamides, dihydrostreptomycin, and streptomycin.