Outbreaks of gangrenous dermatitis in poultry chickens in Argentina

REDONDO, ENZO A.; REDONDO, LEANDRO M.; DELGADO, F; FERNANDEZ-MIYAKAWA, MARIANO E.

Atlanta

Congreso; International Poultry Scientific Forum; 2018

Southern Poultry Scientific Society

Gangrenous dermatitis (GD) is a disease of turkeys and chickens causedby Clostridium perfringens, C. septicum and/or Staphylococcus aureus.Sudden and quick rise in deaths is often a first signal of a GD outbreak.The disease is characterized by necrosis of different skin areas and severe cellulitis of the subcutaneous tissue, in breast, abdomen, wing, orthigh. This work describes the pathological and bacteriological findingsof chickens from 4 outbreaks from different farms. The disease occurredendemically with low morbidity and summer mortality peaks. Affectedanimals were 35 d or older, corresponding to the shift of feed wit no antibiotic. In each of these outbreaks, a complete necropsy of 3 healthy birdsand 4 with clinical signs was performed. In all cases, sick animals showedgangrenous foci prone to crackling with dark skin in ventral region, whichextended caudally. Subcutaneous tissue showed an extensive blood-tingededema and emphysema. The muscle was observed discolored, with a grayish color that extended in depth and hemorrhagic stippling surface. Pairedsamples from each animal skin and subcutaneous tissue, pectoral musclesand different portions of the intestine were taken for bacteriological andhistopathological studies. Bacteriological analysis resulted in coloniespositives for C. perfringens and C. septicum, confirmed by biochemicaltests and PCR. The duodenum of all sick animals presented congestivemucosa, with muco-hemorrhagic content in some cases. Microscopicchanges were characterized by nonsuppurative lymphangitis and edema,nonsuppurative panniculitis with bleeding and presence of Gram positivebacilli in skin and subcutaneous. The underlying skeletal muscle presentedpredominantly interfascicular mononuclear infiltrate, muscle fibers showing different degrees of vacuolar degeneration, hyaline and even coagulation necrosis. In duodenal mucosa, villus atrophy and pseudomembraneswas observed with thickening of lamina propia and mononuclear inflammatory infiltrate with few heterophils, and diffuse bleeding areas. A diagnosis of dermatitis/panniculitis gangrene of a co-infection of C. perfringens and C. septicum is suggested. Further work is necessary to testeffective strategies to control GD in endemic areas of poultry production