de Heus et al.
Severe neurologic disease in a horse caused by tick-borne encephalitis virus, Austria, 2021
Viruses. 2023;15(10):2022. doi:10.3390/v15102022

In TBE endemic areas, horses can be infected by TBE virus mainly by infected Ixodes ricinus ticks (see Snapshot week 22/2023), but they rarely develop clinical symptoms (see Snapshot week 51/2022).

Recently, TBE was analyzed in a 16-year-old Friesian gelding in Austria. The horse had neurologic disease manifesting as ataxia, episodes of compulsive walking, presumed blindness, and the horse had a fever of 38.8°C. Postmortem histological findings were also reported.

IgG antibodies against TBE virus was found positive (>500 U/ml), and IgM antibodies were borderline. Confirmation resulted in neutralizing antibodies with a titer of 1:226.

RT-qPCRs of brain tissue were positive for TBE virus. Sequencing revealed that the genome was of the European subtype. Thus far, there is no further information regarding the pathogenicity of different TBE virus subtypes in horses which requires further investigation.

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