GANGRENOUS DERMATITIS IN BROILER-CHICKENS

Gangrenous dermatitis was observed in two flocks with 6000 and 9000 br oilers. The diseases started at the age of 5 weeks, the morbility and mortality were approx. 4 to 5%. The affected animals showed diarrhoea, faintness and gradually developing weakness before death. The gross p athological and histopathological examinations revealed larger areas w ith loss of feather, enlargement of skin, blushing and oedema mainly i n the skin of legs and dorsal and occasionally also in other regions ( Fig. 1). In different areas, crusting or necrosis of skin and coagulat ive or colliquative necrosis of stratified epithelium could also be ob served. Serous-bloody infiltration of subcutaneous connective and the neighbouring muscular tissues (Figs 2 and 3), occasionally small gaseo us vesicles, necrosis of muscular fibres and 6 to 10 mu m long Gram po sitive bacteria could also be detected (Fig. 4). Besides, acute enteri tis and signs of the passing Gumboro disease could also be observed. T he bacterial strains isolated under anaerobic conditions from the subc utaneous connective tissue and muscles proved to be Clostridium septic um in the basis of their cultural and biochemical characteristics (Tab le). The isolated bacterial strains killed the parenteral (im.) inocul ated experimental animals (rabbits, chickens and guinea pigs) within 2 4 to 48 hours post infection. In the case of the authors mass incidenc e of diarrhoea anticipated the very rarely observed gangrenous dermati tis, known in the literature as wound infection, however injuries of s kin were not observed. According to the authors' opinion, besides diar rhoea, the immunosuppressive status of animals as a result of the seve re, irreversible damage of bursa of Fabricius caused by the previously passed off bursitis was also an important predisposing factor in the development of the disease.