Gumboro disease is caused by a small RNA virus which infects the bursa of fabricius and other organs of the bird leading to high mortality in chickens of varying ages, but usually young birds.
As the bursa is involved in the production of white blood cells responsible for antibody production, infection can lead to immunosuppression, poor growth and secondary infections such as coccidiosis.
Aetiology
The virus is long lasting in the environment and spread in faeces, dust, wind and other vectors such as pets, humans and vehicles. It is difficult to disinfect in a poultry shed and will stay in the soil for years.
Signs
The virus usually affects young chickens and often between 2 and 7 weeks of age. The disease is worse in rapidly growing meat strain male birds than in layers. Often mortality can be as much as 10% over a few days. If the birds survive, or depending on the age of the bird when infected there can be long term reduction in immunity. On post mortem there is blood splashing on the thigh muscles and the bursa is enlarged and often filled with blood. The kidneys are inflamed and the carcass fevered. Diagnosis is by post mortem or blood testing.
Control
The best control is by high levels of biosecurity and the use of vaccines. Contact your vet for more information.
Treatment
There is no treatment for the virus although antibiotics to control secondary infection are often used, vitamins and other products to support the bird in recovery are often useful.