Necrotizing Cellulitis in a Dog

A spayed whippet (3 years of age) was referred and examined for a 3-day history of lethargy, inappetence, and progressive skin lesions. The dog had had an altercation with a cat 4 days before presentation; skin lesions consisted of 2 black, hemorrhagic, deep necrotic ulcers and edema with exudation on the ventral thorax. Skin cytology revealed bacterial organisms. The dog was treated with IV ciprofloxacin and ampicillin–sulbactam. A working diagnosis of necrotizing cellulitis and/or fasciitis was made. Culture revealed heavy growth of Pasteurella multocida (a small, nonmotile, Gram-negative coccobacillus commonly found in the nasopharynx of cats), and histological findings confirmed necrotizing cellulitis. The dog underwent surgical debridement and was discharged with 7 days of oral antibiotics. Ultimately, skin grafting was needed to close the surgical site. Six months postpresentation, the lesion was healed and cosmetically acceptable.

CommentaryComplications of Pasteurella spp infections in cats and humans are well recognized. Although this may be the first reported case of necrotizing cellulitis resulting from P multocida in a dog, it is unlikely to be the only case. Given that the organism is spewed from the oral cavity of cats when they hiss, any lesion (likely imparted by a claw) could be inoculated with P multocida. Clinical clues included the history and 2 ulcerated areas (likely teeth marks). Any rapidly progressing skin disease, regardless of whether it is associated with systemic signs of illness, requires aggressive diagnostic investigation: cytology, skin scrapings for Demodex spp, skin culture, and skin biopsy. Pending culture results and skin biopsy, cytology can help guide treatment.—Karen A. Moriello, DVM, DACVD

SourceCat scratch-induced Pasteurella multocida necrotizing cellulitis in a dog. Banovic F, Linder K, Boone A, et al. VET DERMATOL 24:463-e108, 2013.