Acquired equine polyneuropathy of Nordic horses: A conspicuous inclusion body schwannopathy.

•Acquired equine polyneuropathy in Nordic horses is an emerging, potentially fatal disease.•We present a case-series of in depth investigation of peripheral nerve samples and muscle biopsies of affected horses.•We confirmed a uniform histopathological picture in all cases.•Findings suggest an impairment of Schwannocytic protein metabolism accompanied by autoimmune events.