Polyneuropathy of Finnish horses characterised by inflammatory demyelination and intracisternal Schwann cell inclusions.
BACKGROUND
A neurological disorder characterised by pelvic limb metatarsophalangeal joint extensor paresis has been observed in numerous horses in Scandinavia for the last decade. Very little has been formally reported and there have been no detailed assessments of the neurological signs or neuropathological lesions.


OBJECTIVE
To describe the epidemiological and pathological features of an outbreak of 'Scandinavian knuckling syndrome' in a riding stable in southern Finland.


METHODS
Clinical neurological examination of 4 cases and neuropathological assessment of tissues of one case were performed.


RESULTS
Eleven out of 17 horses fed on ryegrass from a common source showed progressive clinical signs of metatarsophalangeal extensor paresis necessitating euthanasia of 7 horses. Nervous system lesions in one horse consisted of a novel demyelinating, mildly inflammatory peripheral neuropathy, with BiP/GRP positive rough endoplasmatic reticulum Schwann cell inclusions.


CONCLUSIONS
The clinical signs and lesions documented differ from any previously described equine polyneuropathy and suggest a primary Schwann cell lesion.


CONCLUSIONS
The classification of this disease as a novel demyelinating polyneuropathy may assist focused epidemiological investigations.
Hahn
C N
CN
Division of Veterinary Clinical Science, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
Matiasek
K
K
Syrja
P
P
Jokinen
T S
TS
Macintyre
N
N
Tulamo
R M
RM
D000818:Animals; D005387:Finland; D006734:Horse Diseases / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D008683:Metatarsophalangeal Joint / Q000473:pathology*; D009460:Neurologic Examination / Q000662:veterinary; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D011115:Polyneuropathies / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D012583:Schwann Cells / Q000473:pathology*