Strokes in dogs are VERY rare. Strokes involve acute blockage or rupture of a blood vessel in the brain, and subsequent brain haemorrhage. This causes an acute onset of focal neurological signs, which vary depending on the site, extent and time course of the stroke. Most common signs are weakness localized to one side of the body.
Causes in dogs include blood clotting disorders (eg. Ingestion of rat bait), trauma, high blood pressure, brain tumours and malformation of blood vessels within the brain.
Prognosis depends on the severity of the stroke and if the underlying cause is correctable.
A common misnomer of strokes, and more common disease in dogs is Canine Idiopathic Vestibular Disease or ‘old dog vestibular disease’. This is NOT in fact a disease of the brain, but of the inner ear. Middle aged to older dogs are generally affected, of any breed or sex. Clinical signs are usually acute in onset and one-sided. They may be preceded by or include nausea or vomiting. The signs include head tilt, rolling eyes, and circling.
Diagnosis involves excluding other causes of inner ear disease eg. Severe otitis (Infection), polyp or tumours via imaging. This may simply be via an otoscope or require radiographs or advanced imaging.
Treatment is supportive, and may require hospitalization, intravenous fluids and anti-nausea medication if severe.
The prognosis is good, most exhibit improvement in 3 days, and recover over 10-14 days.
A residual head tilt may occur.