Canine double hemorrhage model of experimental subarachnoid hemorrhage.

Several animal subarachnoid hemorrhage (SAH) models have been proposed for the investigation of cerebral vasospasm. We describe the experimental procedures of a canine double-SAH model and also examine the model based on the canine physiological parameters and occurrence of angiographic delayed cerebral vasospasm using magnetic resonance (MR) imaging and digital subtraction angiography. Autologous blood was injected twice on days 1 and 3 in 36 beagles. All animals showed delayed angiographic vasospasm in the vertebrobasilar arteries on day 7. The degree of vasospasm was 29-42 % of the arterial caliber. MR imaging did not show any ischemic change. This animal model can produce definite delayed vasospasm without detectable cerebral infarction on MR imaging. The canine SAH model is suitable for the quantitative and chronological study of delayed angiographic vasospasm, but not for investigating early brain injury and delayed cerebral ischemia.