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| Dry pox on chicken |
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| Dry pox on turkey |
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| Wet pox on Turkey |
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| Wet and dried combined |
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| Wet pox on the upper respiratory tract of chicken |
It is an infectious disease of poultry (Chicken, turkeys,pigeon etc) characterized by proliferative lesions in the skin that progress to thick scabs (cutaneous form) and by lesions in the upper GI and respiratory tracts (diphtheritic form). Virulent strains may cause lesions in the internal organs (systemic form).
There are two types of fowl pox;
Dry pox
While dry pox generally does not increase mortality, a severe outbreak can cause drops in egg production up to 15%. A bird infected with dry pox will develop proliferative scabs on unfeathered areas of skin, and the flock will display a high level of morbidity. An infection in pullets will result in low mean body weight of the flock
Wet Pox
Tracheas can appear reddened or hemorrhagic during certain stages of the disease. The trachea wall is thickened with proliferative, inflamed, often patchy lesions on the interior surface. Mortality occurs when the lesion totally occludes the larynx or the upper part of the trachea.
Wet pox lesions can also be found in the mouth or conjunctiva of the eye.
Wet pox in trachea, patchy lesions.
DIAGNOSIS
Dry pox
Dry pox can be identified visually by the characteristic scabs on the featherless areas of the bird.
Wet pox
Diagnosis of wet pox can be complicated by similar appearing lesions of other respiratory diseases. The only conclusive way to confirm wet pox is by using histopathology on suspect lesion tissue fixed in formalin. The presence of eosinophilic intracytoplasmic inclusion bodies (Bollinger bodies) is diagnostic for pox virus infection.
TRANSMISSION
The virus contained in the scabs contaminates the environment and remains infective for many months.
The virus is transmitted via;
• Mechanical transmission is considered the primary method for dissemination of the virus, and infection can occur through injured or lacerated skin. Mechanical vectors such as insects, can easily carry pox virus and may deposit the virus on susceptible birds. Flies may walk on the eyes of birds, leaving virus behind, and mosquito bites can result in rapid spread of pox throughout the farm.
• Airborne transmission is also suspected in many cases of wet pox.
• In a contaminated house, the infection can spread easily from bird to bird, cage to cage, and by the standing water in drinking cups.
PREVENTION AND CONTROL
Because there's no effective cure, prevention and control is the best measure for keeping flocks healthy.
•Proper vaccination
• Adhere to strict biosecurity measures in the farm
• Control the proliferation of insects colonies by regularly disinfecting the environment.
Note:
Vaccination is practiced based on history of exposure—revaccination, if necessary, can be done in the face of an outbreak because pox infections are usually slow spreading.
In the event of an outbreak, liquid iodine disinfectant (used for disinfecting water lines) added to the water appears to aid in mortality reduction.
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