A study on avian cellulitis in broiler chickens

Abstract

Avian cellulitis in broiler chickens, especially on the thighs and abdominal wall, has been observed more frequently in recent years. In the present study, over a one-year period 98 broiler carcasses with cellulitis were diagnosed at slaughterhouse. The lesions were characterized by thickening and brown discoloration of the skin. A fibrinopurulent exudate with some caseation was seen in the subcutaneous tissues. Microscopically, hyperkeratosis, thickening of the dermis, infiltration of mononuclear cells and heterophils, along with fibrinocaseous exudates, were present. In 90 of the 98 (91.8%) broiler bacteriological samples E. coli was isolated, and in 82 (91.1%) of these samples it was the only bacterial species found. Serotyping results revealed that E. coli isolates were distributed among 6 different serotypes. The most prevalent serotype was O78 (52.2%). In addition, Staphylococcus aureus and Actinomyces pyogenes were isolated from 12 and 2 cases, respectively. This study confirms the frequent association of E. coli with cellulitis lesions in broiler chickens, along with isolation of S. aureus and A. pyogenes. The latter have not been reported in the previous studies.