Atrophic rhinitis in swine. Atrophic rhinitis in swine. Shown are transverse sections of the nasal cavities of pigs exhibiting pathological symptoms of atrophic rhinitis ranging from mild (left panel) to moderate (middle panel) to severe (right panel) caused by infection with toxinogenic P. multocida. (Photos courtesy of the University of Illinois Veterinary Diagnostics Laboratory, Urbana, IL; reproduced with permission.) Brenda A. Wilson, and Mengfei Ho Clin. Microbiol. Rev. 2013; doi:10.1128/CMR.00024-13