Borna Virus Ruled Out for Diallo BB's Untimely Passing

Dressage

Germany

Jessica von Bredow-Werndl has communicated that the borna virus has been ruled out as cause leading to Diallo's untimely passing.

Owners Von Bredow-Werndl, Beatrice Burchler-Keller and Anette Göbelsmann-Schweitzer suffered a massive blow on 6 January 2026 when they were forced to put Diallo BB to sleep after a very sudden and heavy illness.

The 11-year old Hanoverian (by Dancier x Floriscount) and brand new 2025 Otto Lörke prize winner became very ill on Monday 5 January and was immediately brought to the equine clinic, where his condition continued to worsen, ultimately leading to the decision to euthanize the horse.

Initially it was suspected that the Borna virus caused the horse's demise. Borna disease (BD) is an infectious, sporadic neurological disease caused by Borna disease virus. It is an acute or subacute, often fatal viral encephalomyelitis of horses, mule, donkeys and occasionally of sheep. Borna disease virus affects the central nervous system.

Investigations were carried out in finding the actual cause of Diallo's sudden illness.

Von Bredow-Werndl confirmed to Eurodressage that a necropsy and additional blood work were done, which led to the conclusion that "all regionally relevant viruses (including Borna virus) can now be ruled out."

She added, "following the exclusion of further differential diagnoses, an unpredictable underlying cause, such as a cerebral infarction, represents a possible explanation."