OBJECTIVE: To further understand spatial relationships of common carotid arteries to adjacent structures through evaluation of computed tomographic angiograms in dogs. ANIMALS: 24 pet dogs. PROCEDURE: A database was searched for triplanar computed tomographic angiograms that included the heart base caudally and the 5th cervical vertebra cranially, without macroscopic abnormalities. Measurements included brachiocephalic trunk length, common carotid arteries' position relative to the trachea, transverse (axial) thoracic height and width, manubrium length, and length of the 7th cervical vertebra (C7). RESULTS: Measurements (mean + SD) included brachiocephalic trunk length = 3.65 ± 1.34 cm ( CONCLUSION: Some or all measurements were feasible in all dogs. Understanding interindividual variation in spatial relationships is pertinent to differentiating normal from abnormal, for surgical planning, and possibly for elucidating the pathogenesis of certain disorders. CLINICAL RELEVANCE: It is possible to obtain these measurements in dogs. This technique could be applied to subgroups of dogs (