We report details of the first seven equine cases of confirmed West Nile neuroinvasive disease in Austria. The cases presented during summer and autumn of 2016 (n = 2), 2017 (n = 3) and 2018 (n = 2). All horses showed gait abnormalities and 6 of 7 horses exhibited fasciculations and/or tremors, and we provide video recordings of these. Three horses also showed cranial nerve involvement. Following rapid improvement, three horses were discharged. Four horses were euthanized due to the severity of clinical signs and subjected to neuropathological examination. West Nile virus (WNV) lineage 2 nucleic acid was detected in 5 of 7 horses, and WNV-specific neutralizing antibodies in all 7 horses. In addition, serologic evidence of WNV infection was found in two out of fourteen in-contact horses. Horses may be considered a sentinel species for human WNV infections, integrating human and veterinary medicine and thus contributing to the one health concept.

Department of Basic Medical Sciences College of Medicine Mohammed Bin Rashid University of Medicine and Health Sciences Dubai UAE

Institute for Veterinary Disease Control Mödling Austrian Agency for Health and Food Safety Ltd Mödling Austria

Institute of Vertebrate Biology Czech Academy of Sciences Brno Czech Republic

Section Equine Internal Medicine University Equine Hospital University of Veterinary Medicine Vienna Vienna Austria

Viral Zoonoses Emerging and Vector Borne Infections Group Institute of Virology University of Veterinary Medicine Vienna Vienna Austria

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