Self-mutilation in mice associated with otitis media.

Mutilation of the external ear and adjacent tissues was an enzootic problem in outbred Mcr:(ICR) breeder mice in a commercial colony. Necropsy examination of affected and randomly selected, nonaffected adult breeder mice revealed a probable association of the cutaneous lesions with suppurative otitis media. Several microorganisms, including Mycoplasma pulmonis and Pasteurella pneumotropica, were isolated from the tympanic bullae.