Infectious Coryza(IC)is a highly contagious acute respiratory disease of chicken caused by the bacteria Avibacterium paragallinarum (formerly called Haemophilus paragallinarum), a gram-negative nonmotile bacterium. It often affects the upper respiratory tract of chickens but has been also described in quails,guinea fowls, pheasants and parrots. Birds of all ages are susceptible. The disease is well known in laying hens although often goes unnoticed in subclinically infected broilers due to difficulties of the standard bacteriological methods. On the other hand, it is important to differentiate infectious coryza caused by Avibacterium paragallinarum from “coryza of turkeys", which is completely different and is caused by Bordetella avium.
Animals Affected
IC primarily affects;
• Chickens.
• Turkeys,
• Ducks, and
• Other wild avian species appear to be refractory to the infection. The disease has no public health significance for humans(not zoonotic).
Chickens of all ages are susceptible; however the disease is usually less severe in young birds. In the absence of concurrent infection, infected birds typically recover in 2-3 weeks.
Hens in lay typically have a shorter incubation period and the course of the disease tends to be longer. Birds that recover frequently become chronic carriers
How IC spreads
IC primarily spread through
• Chronically infected carrier birds in contact with vulnerable ones
• Airborne
• Contaminated drinking water.
Both commercial chickens as well as village chickens appear to be equally at risk. The disease can cause significant economic losses in intensive poultry operations, especially in multi-age farms. In developing countries, stress factors and the presence of concurrent infections frequently exacerbate losses.
Clinical Signs
The incubation period for IC is approximately 1-3 days. The severity of infection varies depending on the age, breed, environmental stress, and presence of concurrent infections.
Symptoms include;
•Depression especially in young chickens when the disease is in mild form.
• Nasal discharge
• Sneezing.
• Swelling of the face.
• Loss of appetite
• Reduced egg production
• Poor growth
• Swollen eyelids that do not open
• Swollen waffles.
In the severe form, typically seen in young adults, there is an acute infection of the upper respiratory tract. Signs may include serous to mucoid nasal discharge, swelling of the infraorbital sinuses, facial edema including swollen eyelids that do not open, swollen wattles and intermandibular space, and conjunctivitis. If the lower respiratory tract becomes involved, rales may be observed. Signs usually persist for only a few weeks, however, if secondary infection occurs, the swelling can persist for months. Feed consumption, egg production, and growth are often severely reduced.
Post-mortem Lesions
On post-mortem examination, gross lesions may be found on the mucous membranes of the nasal passages, sinuses, and ocular conjunctiva. Findings may include inflammation and catarrhal lesions. Subcutaneous edema may be found in the face, wattles, and intermandibular region. Rarely, pneumonia and airsacculitis may be present.
Differential Diagnosis
Swelling of the face and wattles must be differentiated from chronic fowl cholera, Newcastle disease, infectious bronchitis, avian influenza, avian metapneumovirus (swollen head syndrome), mycoplasmosis, and infectious laryngotracheitis. A nonpathogenic species, Avibacterium avium, may be cultured from the sinus of chickens, either alone or in combination with A. paragallinarum. A. paragallinarum is catalase negative, while nonpathogenic species are catalase positive.
Diagnosis
A smear of sinus exudate can be made and Gram stained, which will reveal Gram-negative, bipolar-staining rods with a tendency toward filament formation. The sinus exudate should be cultured on a blood agar plate, previously streaked with Staphylococcus aureus. This will serve as a feeder colony by providing V-factor. The plate should be incubated in a candle jar or CO2 incubator. Tiny dewdrop-like colonies of A. paragallinarumc will develop adjacent to the feeder colony. The organism can be further identified by biochemical tests or polymerase chain reaction (PCR). Serologic tests include agar gel precipitation and hemagglutination-inhibition.
Prevention and Control
• Management practices that include all in, all out of flocks, help to prevent and control the disease.
• Antimicrobial therapy is very effective but it should be used according to specific residue regulations in birds producing eggs for human consumption.
•Commercially available IC vaccines are inactivated whole cell bacterins. They may contain one or several isolates representing various serogroups. In severe outbreaks, autogenous vaccines are commonly used. Broilers are not commonly vaccinated against IC. In many countries, replacement layers and breeders receive two vaccinations subcutaneously or intramuscularly, at least four weeks apart, before twenty weeks of age.
LAYER MANAGEMENT
EFFECTIVE RAT CONTROL MEASURES
PREVENT HENS FROM EATING THEMSELVES
Recommended Drugs for IC Control
•Streptomycin,
•Dihydrostreptomycin,
• Sulphonamides,
• Tylosin,
• Erythromycin.
Always reach out to your Animal health professional for advice and guidance on how to handle diseases on your farm.
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Animals Affected
IC primarily affects;
• Chickens.
• Turkeys,
• Ducks, and
• Other wild avian species appear to be refractory to the infection. The disease has no public health significance for humans(not zoonotic).
Chickens of all ages are susceptible; however the disease is usually less severe in young birds. In the absence of concurrent infection, infected birds typically recover in 2-3 weeks.
Hens in lay typically have a shorter incubation period and the course of the disease tends to be longer. Birds that recover frequently become chronic carriers
How IC spreads
IC primarily spread through
• Chronically infected carrier birds in contact with vulnerable ones
• Airborne
• Contaminated drinking water.
Both commercial chickens as well as village chickens appear to be equally at risk. The disease can cause significant economic losses in intensive poultry operations, especially in multi-age farms. In developing countries, stress factors and the presence of concurrent infections frequently exacerbate losses.
Clinical Signs
The incubation period for IC is approximately 1-3 days. The severity of infection varies depending on the age, breed, environmental stress, and presence of concurrent infections.
Symptoms include;
•Depression especially in young chickens when the disease is in mild form.
• Nasal discharge
• Sneezing.
• Swelling of the face.
• Loss of appetite
• Reduced egg production
• Poor growth
• Swollen eyelids that do not open
• Swollen waffles.
In the severe form, typically seen in young adults, there is an acute infection of the upper respiratory tract. Signs may include serous to mucoid nasal discharge, swelling of the infraorbital sinuses, facial edema including swollen eyelids that do not open, swollen wattles and intermandibular space, and conjunctivitis. If the lower respiratory tract becomes involved, rales may be observed. Signs usually persist for only a few weeks, however, if secondary infection occurs, the swelling can persist for months. Feed consumption, egg production, and growth are often severely reduced.
Post-mortem Lesions
On post-mortem examination, gross lesions may be found on the mucous membranes of the nasal passages, sinuses, and ocular conjunctiva. Findings may include inflammation and catarrhal lesions. Subcutaneous edema may be found in the face, wattles, and intermandibular region. Rarely, pneumonia and airsacculitis may be present.
Differential Diagnosis
Swelling of the face and wattles must be differentiated from chronic fowl cholera, Newcastle disease, infectious bronchitis, avian influenza, avian metapneumovirus (swollen head syndrome), mycoplasmosis, and infectious laryngotracheitis. A nonpathogenic species, Avibacterium avium, may be cultured from the sinus of chickens, either alone or in combination with A. paragallinarum. A. paragallinarum is catalase negative, while nonpathogenic species are catalase positive.
Diagnosis
A smear of sinus exudate can be made and Gram stained, which will reveal Gram-negative, bipolar-staining rods with a tendency toward filament formation. The sinus exudate should be cultured on a blood agar plate, previously streaked with Staphylococcus aureus. This will serve as a feeder colony by providing V-factor. The plate should be incubated in a candle jar or CO2 incubator. Tiny dewdrop-like colonies of A. paragallinarumc will develop adjacent to the feeder colony. The organism can be further identified by biochemical tests or polymerase chain reaction (PCR). Serologic tests include agar gel precipitation and hemagglutination-inhibition.
Prevention and Control
• Management practices that include all in, all out of flocks, help to prevent and control the disease.
• Antimicrobial therapy is very effective but it should be used according to specific residue regulations in birds producing eggs for human consumption.
•Commercially available IC vaccines are inactivated whole cell bacterins. They may contain one or several isolates representing various serogroups. In severe outbreaks, autogenous vaccines are commonly used. Broilers are not commonly vaccinated against IC. In many countries, replacement layers and breeders receive two vaccinations subcutaneously or intramuscularly, at least four weeks apart, before twenty weeks of age.
LAYER MANAGEMENT
EFFECTIVE RAT CONTROL MEASURES
PREVENT HENS FROM EATING THEMSELVES
Recommended Drugs for IC Control
•Streptomycin,
•Dihydrostreptomycin,
• Sulphonamides,
• Tylosin,
• Erythromycin.
Always reach out to your Animal health professional for advice and guidance on how to handle diseases on your farm.
Please Follow us by clicking on the 3 parallel lines at the top right corner of this page on your device
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