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Updated: Feb 7, 2026

Protocol for Isolating the Mouse Circle of Willis
Published on: October 22, 2016
Anatomical variations in the circle of Willis in canines
Toshiyuki Tanaka1,2, Hideo Akiyoshi1, Keiichiro Mie1
1Laboratory of Veterinary Surgery, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano-shi, Osaka, Japan.
Abstract:
The circle of Willis (CW) supplies blood to the brain. In humans, anatomical variations in the CW are an important risk factor for transient ischaemic attack and stroke. In canines, anatomical variations in the CW have not been reported. The aim of this study was to determine anatomical variations in the CW in dogs by magnetic resonance angiography. Normal configuration of the CW was observed in 82%, aplasia of the precommunicating segment of the rostral cerebral artery was observed in 14%, and aplasia of the rostral communicating artery was observed in 4% of dogs included in the study.
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