Causative agent
- FP virus, family Poxviridae
Differential diagnosis
- Vesicular dermatitis (photosensitization)
- Infectious laryngotracheitis
- Trichomonas gallinae
- T-2 toxin
- The effects of excess ammonia gas
1. History taking
- Slow-spreading disease of all ages, sexes and
breeds of chickens, turkeys and many other birds
- Mosquitoes-transmitted outbreaks may result in
rapid spread
2. Clinical examination
- Transient drop in egg production and a reduced
growth rate in young chickens
- Signs vary with the two forms of pox cutaneous
form
- Common and nodular lesions on the unfeathered
skin of the head, neck, legs or feet
- Diphtheritic form (wet pox)
- Lesions in the upper respiratory or digestive tract
cause dyspnea, inappetence
- Lesions in nasal cavity or conjuctiva cause nasal
or ocular discharge
- Low to moderate mortality due to suffocation,
starvation and dehydration
3. Necropsy
- Cutaneous lesions : vary according to the stage of
nodular formation. At first appear as small white
foci then rapidly increase in size and become
yellow
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- Papules are formed by the 5th or 6th day, followed
by the vesicular stage with formation of extension
thick lesions and become rough and gray or dark
brown
- Dipheritic lesions : slightly elevated, white opague
nodule on mucous membrane and rapidly increase
in size and become yellow, cheesy necrotic
diptheritic membrane and usually predominate in
the mouth but may be present in the sinuses,
nasal cavity, conjunctiva, pharynx, larynx, trachea,
esophagus
4. Histopathological observation
- Hyperplasia of the epithelium and enlargement of
cells with eosinophilic A-type cytoplasmic
inclusion bodies (Bollinger bodies) in various stages
of development
- Infiltration of inflammatory cells in affected area
5. Virus isolation
Specimen : nodular lesions
Method : chick embryo inoculation at 9-11
days of age by CAM route and
observation of focal white opague
pocks on the CAM or generalized
thickness of the CAM
6. Virus identification
- Intracytoplasmic inclusion bodies in stained
section of infected CAM
Control
- Vaccination
- Good sanitation and management
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