Strokes are reported infrequently in dogs, but with advances in technology, they are being identified more often. There are two main types of stroke: ischemic and hemorrhagic.
Ischemic strokes are more common, and an underlying cause is found in about 50% of cases. The most common concurrent medical conditions found in dogs are hyperadrenocorticism, chronic kidney disease, hypothyroidism and hypertension.
Hemorrhagic strokes are rare and have been reported secondary to rupture of congenital vascular abnormalities, brain tumors, intravascular lymphoma, cerebral amyloid angiopathy and impaired coagulation. Signs are typically peracute in onset, and then they plateau. Worsening edema can sometimes lead to progression of neurologic signs
MRI is the imaging modality of choice. CT can detect hemorrhage and is useful for ruling out mimics of stroke, but it is not very sensitive in detecting ischemic changes. Ancillary diagnostic tests for ischemic strokes include CBC, chemistry, UA, serial blood pressure measurements, urine protein/creatinine ratio, d-dimers, endocrine testing, thoracic radiographs, abdominal ultrasound and echocardiography.
Ancillary diagnostic tests for hemorrhagic stroke include serial blood pressure measurement, CBC, chemistry, BMBT, PT/PTT, thoracic radiographs and abdominal ultrasound. Treatment, regardless of type, includes supportive care and management of neurologic and nonneurologic complications, as well as treating any underlying causes.
Most cases of ischemic stroke recover within a few weeks with just supportive care. Hemorrhagic stroke is far less common, but associated with higher mortality. The risk of neurologic deterioration is highest in the first 24 hours. Dogs with concurrent medical conditions have significantly shorter survival times and are more likely to suffer from subsequent infarcts.