21 quick facts you should know about Gumboro disease
1. Gumboro disease is also known as Infectious Bursal Disease.
2. It is an important viral disease of poultry throughout the world.
3. Clinically it affects young Chicken, usually up to 6 weeks of age.
4. The name “Gumboro” Disease was initially given to the condition because it was first recognized in the Gumboro district of Delaware, USA.
5. Following infection of growing susceptible Chicks, the virus is excreted in feaces for 10 – 14 days and it is very stable and remains highly infectious in the poultry environment for many months.
6. Young Chicks with maternally derived antibody (MDA) are immune to infection while antibody levels are high but become susceptible when titres drop.
7. The virus affects lymphoid tissue, causing destruction of lymphoid cells within the bursa of Fabricius, the spleen and caecal tonsils.
8. The disease leads to immunosuppression which also leads to lower resistance to disease and sub – optimal responses to vaccines given during the time of infection.
9. The severity of signs is dependent upon age, breed and MDA level of the Chick as well as the virulence of the virus.
10. The signs include depression, white watery diarrhea, soiled vents, and lack of appetite, ruffled feathers, and reluctance to move, closed eyes and death.
11. Morbidity (rate of occurrence) ranges from 10%, occasionally reaching 50%.
12. The milder form of disease may result in little or no signs other than sub-optimal growth and sometimes an increase in other diseases, and reduced response to vaccines.
13. The course of the disease in the individual Chick is short leading rapidly to death or recovery.
14. The cause of the disease in the flock where protective Maternally Derived Antibody (MDA) levels vary – it is prolonged with chicks succumbing when their antibody levels drop on the flock basis, mortality reaches a peak 3-4days post infection.
15. The carcasses of birds dying from this infection are dehydrated.
16. The bursa is first enlarged, inflamed, oedematous and cream coloured, and after about 3 – 8 days atrophies.
17. The history, clinical signs and gross lessons are adequate for recognition of acute disease.
18. Due to the stable nature of the virus and the large amounts excreted following infection, it is practically impossible to remove all sources of infection once a rearing site has been contaminated.
19. There is evidence that thorough cleaning and disinfection of houses between flocks and the practice of “all in all out management reduces the challenge virus.
20. Formaldehyde and lodophors have been shown to be effective disinfectants.
21. In practice, control of Gumboro disease is dependent upon the use of vaccines.