Paradoxical vestibular syndrome in the dog: where is the lesion
9-year-old Boxer with progressive loss of balance over 3 weeks. It is alert.
| Parameter | Result | Reference |
|---|---|---|
| Head tilt | To the right | Absent |
| Postural reactions | Delayed in left limbs | Normal |
| Gait | Left thoracic limb hypermetria | Normal |
| Menace response | Absent in left eye; avoids obstacles | Present |
Where is the lesion located?
chevron_right Show answer and explanation
A. Right middle and inner ear (peripheral vestibular)
A peripheral lesion does not cause postural deficits or hypermetria. The tilt would also be towards the side of the lesion.
B. Right forebrain
Forebrain lesions do not cause a head tilt or nystagmus, and an absent menace with preserved vision is not a forebrain feature.
C. Right brainstem
A central right brainstem lesion would cause a tilt and postural deficits on the same side, the right.
D. Left side: cerebellum (flocculonodular lobe or caudal cerebellar peduncle)
Correct. In paradoxical vestibular syndrome the head tilts away from the lesion. The postural deficits, hypermetria and absent menace with preserved vision point to the affected side: the left.
lightbulb Key takeaway
When the tilt and postural deficits are on opposite sides, trust the postural deficits to lateralise. Paradoxical syndrome is always central; in older dogs consider cerebellopontine angle masses (meningioma, choroid plexus tumour) or cerebellar infarcts.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.