[Infestation of a cattle herd with the ear mite Raillieta auris (Acarina, Mesostigmata)]

An infestation with Raillietia auris in a 4 years old cow is reported. For a period of 3 weeks the animal showed an increasing unrest, extreme efforts while trying to feed, and continuous shaking of the head which slanted to the left. After slaughter numerous specimens of the ear-mite R. auris were found in the basic part of the left auditory canal, located in the vicinity of a purulent paste-like plug. Histological examinations of the brain revealed a severe non-purulent meningoencephalitis with necroses of the vascular walls, focal malacia and gliosis. An etiological correlation of these lesions with the mite-infestation, however, is considered to be most unlikely. To the best of our knowledge the occurrence of R. auris in Switzerland was up to now unknown.