Gumboro (IBD): the disease that weakens the whole flock

5 min read · Shiv Sales & Marketing team

Infectious bursal disease (IBD), commonly called Gumboro, is a viral disease of young chickens. It attacks the bursa of Fabricius — the organ where young birds develop the cells that produce antibodies. The result is not only deaths, but a flock whose immune system has been weakened.

Why it matters so much

• Direct losses — sudden mortality, usually in birds around 3–6 weeks of age.
• Immunosuppression — chicks infected very early may show few signs, but their immunity is damaged. They respond poorly to other vaccines (such as Newcastle disease) and fall sick more easily from E. coli and other infections.
• A tough virus — it survives for months in sheds and litter and resists many common disinfectants, so once it is on a farm it tends to stay.

Signs

• Depressed, ruffled birds; reluctance to move
• Whitish, watery droppings; soiled vent feathers
• Pecking at the vent
• Rapid rise in deaths over a few days, then recovery
• On post-mortem: swollen, discoloured or bleeding bursa, and bleeding in the thigh and breast muscles

Vaccination and maternal antibodies

Chicks receive protective antibodies from their mother through the egg. These maternal antibodies protect early in life but also neutralise live Gumboro vaccines given too soon. Vaccinate too early and the vaccine is wasted; too late and field virus may get in first.

That is why IBD vaccine timing is planned around the breeder flock's vaccination and, ideally, blood testing of day-old chicks. Different vaccine types — intermediate, intermediate-plus, and others — are chosen according to the level of field challenge on your farm.

Farm hygiene

• Thorough cleaning, washing and disinfection between flocks, with a product effective against IBD virus
• Removal of all old litter and an adequate empty (downtime) period
• All-in, all-out placement where possible