Clostridial dermatitis and cellulitis: an emerging disease of turkeys.

Clostridial dermatitis of turkeys (CDT) has emerged as a major issue across most geographic regions of the United States. The prevalence and severity of dermatitis has increased over the last several years, since the time it was first reported in 1993. Cellulitis in poultry can be associated with Staphylococcus aureus or Escherichia coli, but the more recent field situation in turkeys is specifically associated with Clostridium spp. The prevalence of cellulitis is relatively low; however, the disease can be devastating in the individual flocks affected. Clostridium septicum, Clostridium perfringens, Clostridium sordelli, and S. aureus can cause cellulitis. Escherichia coli, Streptococcus spp., and other bacteria have occasionally been isolated from birds diagnosed with cellulitis. CDT appears as excessive mortality in older birds around 16-18 weeks of age. It has been reported from field experience as early as 7 wk of age. Clinical signs of CDT can range from sudden death to inappetence, depression, leg weakness, recumbency, and ataxia. The disease is characterized by reddish to dark or greenish discoloration of the skin around the thighs, abdomen, keel, tail region, back, and wings. The lesions can extend into the underlying muscles, and there can be gas bubbles under the skin which result in crepitation. Some cases present with dead birds having "bubbly tail," fluid-filled blisters associated with broken feather follicles around the base of the tail. Bubbly tail in breeder toms might not cause excessive mortality, but the lesions are so severe that the birds cannot be used for semen collection. Incidence of mortality from this condition can be severe and acute (i.e., rapid onset of high mortality). The dead birds decompose very quickly. Microscopically, there is necrosis, with or without inflammation of the skin, especially in the dermis and occasionally in the skeletal muscles, associated with large numbers of rod-shaped bacteria. Overcrowding, aggressive birds, poor-wet litter, decreased down time, a contaminated environment including feed and water, poor hygienic conditions, and contaminated vaccines and vaccine equipment, etc., can predispose birds for CDT. Preventative measures and treatment are discussed extensively in this review.