Causative agent
- CIA virus, family Circoviridae
Differential diagnosis
- Infectious bursal disease
- Marek's disease
- Osteopetrosis virus infection
- Erythroblastosis virus infection
- Inclusion body hepatitis
- Vitamin K deficiency
- Intoxication with sulfonamide or mycotoxin
1. History taking
- All ages of chickens are susceptible, the
susceptibility rapidly decreases during the first 2-3
weeks of life
- Vertical spread occurs following primary infection
of in-lay breeders without showing any signs or
other effects but results in clinical disease in their
progeny towards the end of the second week of
life
- Co-infection with other immunosuppressive agents
increases the severity of the disease
2. Clinical examination
- Anorexic depress
- Pallor of the comb and wattle
- Ruffled feathers and increasing daily mortality
- Peak mortality occurs within 5-6 days of onset of
clinical signs and mortality has often declined to
normal levels after a further 5-6 days
- Affected chickens often show focal skin lesions due
to secondary infection leading to gangrenous
dermatitis
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3. Hematology
- Anemia (hematocrit value ranging from 6-26%)
4. Necropsy
- Thymus and bursa of Fabricius atrophy
- Pale, fatty bone marrow
- Ecchymotic skin hemorrhages on the wing, head,
thighs and legs
- Discoloration, swelling of liver, kidney and spleen
5. Histopathological observation
- Panmyelophthisis and generalized lymphoid
atrophy in bone marrow
- Depletion of lymphocytes from the thymus, spleen,
bursa of Fabricius and cecal tonsils followed by
hyperplasia of reticular cells
- Swelling of hepatocytes and dilated sinusoids
6. Virus isolation
Specimen : liver, spleen, feces ,circulating
lymphocytes
Method : MDCC-MSB1 cell culture inoculation
and CPE observation (cell death)
7. Virus identification
- IFA test
- SN test
Control
- Monitoring of breeder flocks for the presence of
immunity to CIA virus before laying
- Good sanitation and management to prevent
immunosuppression
- Vaccination
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