The disease affects immature chickens world wide. Acute infection with classic mild or variant strains results in up to 5% mortality. The variants are more immunosuppressive than the classic strains. Very virulent (vvIBD) virus may kill up to 50% of susceptible flocks.
Avibirnaviruses are immunosuppressive and predispose flocks to intercurrent viral pathogens and secondary bacterial infection.
Infectious Bursal Disease is a major restraint to productivity and profitability in the poultry industries of both industrialized and developing nations.
Flocks are affected acutely and show variable morbidity (5-50%) and rapidly ascending mortality (5-50%), depending upon the pathogenicity of the IBDV strain and the susceptibility of the flock. Affected birds are depressed and show recumbency, ruffled plumage and white diarrhea. There are no characteristic signs specific to IBD.
Riemerella anatipestifer is the principal pathogen responsible for duckling septicemia. Concurrent infections include E. coli, septicemia, salmonellosis and duck virus hepatitis.
Occurrence and Economic Significance
Duck septicemia occurs in all areas where ducklings are reared commercially, resulting in variable morbidity and mortality during the first two weeks of the brooding period.
Direct contact of susceptible ducklings with a contaminated environment. Footpad lesions from defective wire floors predispose to percutaneous infection.
Affected ducklings show depression, ataxia, ocular and nasal discharge and respiratory rales.
Septicemic changes characterized by perihepatitis, pericarditis and fibrinous airsacculitis, hepatomegaly and splenomegaly are observed. In some cases, fibrinous meningitis occur, especially in ducklings which display nervous signs.
Diagnosis is based on isolation and identification of Rimerella anatipestifer from heart blood, liver or brain tissue on either blood agar or trypticase soy agar.
Supportive therapy and administration of water soluble tetracycline may be attempted. Enrofloxacin can be administered in drinking water at a level of 50 ppm for the first 2 days followed by 25 ppm for 4 subsequent days.
Managemental interventions including effective sanitation between placements, avoiding overcrowding and chilling should be implemented.
Multivalent or homologous bacterins have been prepared for administration to ducklings at 1 to 2 weeks of age. A live attenuated vaccine against serotypes 1, 2 and 5 has been developed, which is administered to ducklings by the aerosol route or in drinking water at day-old.
Fowl cholera is a contagious, bacterial disease that affects domestic and wild birds worldwide. It usually occurs as a septicemia of sudden onset with high morbidity and mortality, but chronic and asymptomatic infections also occur.
Newcastle disease is an infection of domestic poultry and other bird species with virulent Newcastle disease virus (NDV). It is a worldwide problem that presents primarily as an acute respiratory disease, but depression, nervous manifestations, or diarrhea may be the predominant clinical form. Severity depends on the virulence of the infecting virus and host susceptibility. Occurrence of the disease is reportable and may result in trade restrictions.
Fowl cholera is the reason for great economic loss of poultry in bangladessh