SEPTICEMIA AND AIRSACCULITIS

Etiology

Pathogenic strains of E. coli, superimposed on primary immunosuppressive and respiratory viral infections.

Occurrence and Economic Significance

Septicemia and air sacculitis resulting from E. coli infection are responsible for decreased growth rate and feed conversion efficiency, elevated flock mortality. Infection of commercial laying and breeding stock during the rearing period may adversely affect subsequent performance.

Flocks infected with vertically transmitted or acquired mycoplasmosis are extremely susceptible to E. coli airsacculitis.

Diets containing aflatoxins or free radicals evolved from peroxidation of lipids will lead to immunosuppression with increased susceptibility to E. coli infection.

Transmission

1. coli is introduced onto poultry farms through contaminated drinking water. High levels of infection occur following deficiencies in routine decontamination of housing, equipment and drinking systems.

Immunosuppressive and respiratory viruses which precipitate infection are transmitted by direct and indirect contact especially on multi-age farms or where biosecurity is defective.

Clinical Signs

• Morbidity of up to 10% occurs during the 10 – 40 day period
• Ascending mortality may attain 50% in immunosuppressed broiler flocks subjected to environmental stress and previous exposure to viral respiratory pathogens and mycoplasmosis

Pathology

• Pulmonary congestion
• Enlargement of the spleen and liver
• Generalized venous congestion
• Perihepatitis
• Pericarditis
• Peritonitis
• Bursal atrophy indicating previous exposure to ibdv is often observed
• Birds surviving acute airsacculitis show stunted growth
• Caseous exudate in the air sacs often accompanied by peritonitis

Diagnosis

Isolation, identification and serotyping of E. coli from heart blood, perivisceral exudate, and liver tissue.

Treatment

Mortality can be suppressed by administration of water soluble furazolidone, sulfonamides, and fluoroquinolones where these drugs are permitted.

Prevention

Chlorination of drinking water to 2 ppm and installation of closed (nipple) drinking systems are recommended.

Alleviation of obvious managemental deficiencies and environmental stress factors will reduce the intensity of respiratory stress.

Appropriate vaccination programs are required to prevent immunosuppressive and respiratory viral diseases.

Breeders can be vaccinated with commercial metapneumovirus vaccines.

Attempts at immunization of broilers have not been successful. Control of IBD, ND, IB by vaccination and improved flock management and provision of chlorinated drinking water will reduce losses.