In the commercial broiler, cellulitis is considered one of the most economically prevalent problems due to the presence of the lesion leading to increased condemnations and carcass downgrading. Clinically cellulitis is a deep infection of broiler chicken skin caused by many bacterial species, mainly Escherichia coli (E. coli) and/ or Staphylococcus aureus (S. aureus), causing severe economic losses in poultry. This study was done on 14-day old broiler Ross 308 chickens subcutaneous (s.c) injected with E. coli and/ or S. aureus to induce cellulitis. Clinical signs, mortality, pathological lesion, and growth performance were determined. Hematological parameters, liver and kidney functions were also recorded. Colistin+ Doxycycline combination (Doxyforte®) was used to control the infection. Clinically, site of infection was appeared red, swollen accompanied with increased skin thickness, postmortem lesions in the 3rd day post infection with s.c. yellowish suppurative exudates, pericarditis and perihepatitis were prominent E. coli infected with hepatic subcapsular hemorrhage mostly in S. aureus groups. Hematological parameters were mostly affected in all infected non-treated groups compared to negative control without significant difference. Histopathological changes of infected non-treated groups showed inflammation of s.c tissue with massive heterophils and mononuclear cell infiltration, hydropic degeneration of the hepatocytes and congested splenic sinusoids. While treated groups showed limited skin inflammatory condition at the site of injection and return of skin to normal color and thickness. Doxycycline+ colistin combination helps in reduction of lesions in treat infected birds, with marked improvement in measured parameters. We recommended active actions to prevent causes and factors helping in including cellulitis, regular lowering bird density, enhancing restrict biosecurity, modulating the vaccination timing, improving management practices, as well as application of probiotics to improve and restore good gut health.
Keywords | Cellulitis, Experimental infection, Broiler chickens, Clinical signs, Pathological lesion, Control, Colistin, Doxycycline, Hematology, Bacterial diseases