Pathological Study of Infectious Bursal Disease in Broilers of Haryana

Infectious Bursal Disease is a highly co ntagious, viral and immunosuppressive disease of poultry. It is one of the most important diseases in poultry as it causes heavy mortality. It produces severe and prolonged suppression of the natural immune responses i.e, immunosuppression. Immunosuppression, in turn, can lead to secondary bacterial infection and vaccination failures. In broilers, immunosuppression is denoted by a high prevalence of viral infections and elevated mortality due to airsacculitis and colisepticemia. Both, broiler and pullet flocks may become refractory to live attenuated vaccines against respiratory diseases such as infectious bronchitis and Newcastle disease (Singh et al.). The deaths resulting from other diseases in many cases are greater than those from Gumboro disease itself. The occurrence of this disease condition resulted in financial losses has been recorded from various parts of the country. The disease has been recently observed in many broiler farms of Panipat, Karnal and Hissar districts of Haryana. In the present study, an attempt has been made to study the clinical and pathological changes of the disease under field condition. A total of seven hundred twenty three birds affected with IBD at Verma poultry farm in Panipat, Haryana, having the flock size of 9000 birds at 18 days of age observed during October 2013, formed the basis of the present study. In addition, three apparently healthy birds were also selected from this farm as control. Following clinical examinations of the affected birds in farm complex, the post-mortem examination was performed at farm level.

On clinical examination, the IBD affected birds revealed inappetence, dullness, depression, and reluctance to move. Some of the birds showed retarded growth, ruffled feathers and white diarrhoea with vent pasting in few birds. The morbidity rate in these farms varied from 8–10%, the medication was started immediately after observation of the disease and mortality rate was controlled to about 3–5% only. The signs of immunosuppression determined by lowered immune response to vaccine with the poor weight gain in the farm.

On post-mortem examination, the haemorrhages were observed at leg muscle. The bursa fabricus was enlarged 2 times with severe pus accumulation in its lumen. In advance condition, on opening of bursa revealed haemorrhages and blood accumulation in its lumen.The disease was treated by giving antiviral drug (Biobooster) in drinking water 1gm/2 Lit. of water, spray of Vircon at 50gm/15 Lit. of water daily and in supportive treatment a Vit. E supplement (E care Se) at the rate of 25ml/100 bird was given.The clinical signs and gross lesions observed in this study were almost similar to those reported earlier (Mazengia et al.). The factors responsible for IBD are risk of infection, strains of virus prevalent in the area, inter current exposure to respiratory viral infections and vaccination failures. The regular monitoring of IBD virus should be component of health program in broilers.