Farm chickens are affected by various viral diseases, and Gumboro is one of the main ones. Chickens are at risk of Gumboro at two months of age. If it is not treated in time, every bird on the farm may die.

It was first identified in 1962 at a place called Gumboro in Sussex, America. Because it attacks the bursa, a lymphatic gland of the chicken, it is also called infectious bursal disease.

Gumboro is caused by a virus called birna. Although it has two serotypes, only one (serotype 1) harms poultry. The virus attacks the bird's bursa of Fabricius, reducing its immunity and feed conversion efficiency. Usually 30 per cent of affected chickens die, and in severe cases even more may die.

Serotype 1 infects only chickens. Serotype 2 is seen in chickens, turkeys, penguins and several wild birds, but it has little effect.

Gumboro, or infectious bursal disease, is a deadly contagious disease. It usually spreads from infected birds and very quickly runs through the whole flock. The virus easily passes from one shed or farm to another. Keeping birds at high density, keeping birds of different ages together, not leaving the shed empty between two batches, poor biosecurity and several other factors can cause Gumboro. It can also come from the parents or from weak immunity.

Chickens with Gumboro show certain signs. They become weak, listless and dehydrated. They have watery droppings that look white like lime. They sit in one place and are reluctant to move. Their feathers look ruffled. Body temperature may rise. The disease starts suddenly and deaths rise. A wet vent is seen.

The disease also brings some internal changes. Blotches of blood are seen on the leg and thigh muscles. The bursa swells, and when cut open shows spots of blood inside. The liver becomes quite large and pale, and the kidneys become enlarged.

Gumboro causes dehydration, leading to a severe electrolyte shortage. For this reason saline water, or as some say molasses water, is recommended. Antibiotics can be given to prevent secondary bacterial infection.

There is generally no treatment for viral diseases, and prevention is the best measure. A vaccine is available, and proper vaccination along with biosecurity can keep flocks free of Gumboro.

Source: Jagonews24. First published in Bengali on The Agro News.