Gumboro disease Is an acute and contagious, viral disease of young chickens characterized by immunosuppression, diarrhea, vent pecking, trembling, incoordination and marked inflammation and enlargement, followed by atrophy, of the bursa of fabricius.Is a member of family Birnaviridae
Gumboro virus is found in faeces of infected birds, infection follows ingestion of infected faeces and contaminated feed, water or litter. Transmission is also between Farms through contaminated equipment and clothing.
IBD occurs primarily in chickens. Clinical signs and mortality are more severe in birds of 3 – 6 weeks old, although can occur inasmuch as there is functional bursa of fabricius (1 – 16 weeks of age).
The onset and recovery from Gumboro disease are sudden. Clinical signs last for 5-6 days. Morbidity and mortality rates of up to 100% and 30% respectively have been recorded. There is reduced flock activity and feed consumption. Sicks birds hurdle together or isolate themselves and stand on spot with drooping tail and head. They are usually depressed, off feed, ruffled feathers, tremble and void greenish- yellow watery diarrhoea.
Gross lesions and post mortem
At necropsy, the lesions seen will depend on the strain of IBDV. For strains that cause a clinical disease, the cloacal bursa is swollen, edematous, yellowish, and occasionally hemorrhagic, especially in birds that died of the disease. Strains of vvIBDV cause similar cloacal bursa lesions, and congestion and hemorrhage of the pectoral and leg muscles can also occur. Some IBDV strains can cause atrophy of the cloacal bursa without the appearance of gross lesions in that organ. Chickens that have recovered from IBDV infections have small, atrophied, cloacal bursas due to the destruction and lack of regeneration of the bursal follicles.
Clinical signs, isolation of IBD virus and identification from bursa and spleen. Immunofluorescence or immunohistochemistry tests, AGPT and ELISA.
Vaccination (serological test for sero-profiling).
Of no value, adopt good husbandry and adequate warmth to reduce severity and passive immunity too.
Economic Importance of Gumboro disease
- Vaccination failure leads to birds loss : it provide job employment opportunity for veterinary doctors
- Research for scientists. i.e the discovery of the vaccine and the struggle to discover drugs
- Source of income to the company, scientists, veterinarians and the county that discover the vaccine .
Dr Alayande Gbenga