Gas Gangrene (Malignant Edema)

Gas gangrene is a necrotizing clostridial infection of soft tissue that affects ruminants, horses, pigs, and occasionally other mammalian and avian species worldwide. The disease is caused by one or more of the following clostridia: Clostridium septicum, C. chauvoei, C. novyi type A, C. perfringens type A, and C. sordellii. This chapter discusses the etiology, epidemiology, pathogenesis, clinical signs, diagnosis, treatment, control, and prophylaxis of gas gangrene. Alpha-toxin (ATX), a β-pore-forming member of the aerolysin family, is considered the main virulence factor of C. septicum. C. perfringens type A is associated with enteric and histotoxic diseases of humans and animals. Prevention and control should be based on immunization of the animals, on strict hygienic measures including surgical hygiene, on navel treatment with antiseptics, and avoidance of soil or fecal contamination of wounds. Proper carcass disposal helps reduce soil contamination with clostridia, but preventing predisposition is the key to controlling infection.