Abdominal Aortic Diameter Appears Unaffected by Systemic Hypertension in Computed Tomography Measurements in Dogs

Dogs with chronically elevated blood pressure require prompt treatment to prevent systemic hypertension-related tissue damage. Non-invasive oscillometry and Doppler sphygmomanom-etry are the conventional techniques to ascertain this indication, but imaging modalities may enable easier blood pressure assessments based on vascular geometry. This area is little studied in canine medicine, with only one report on abdominal ultrasonography, and none on computed tomography (CT). Accordingly, we retrospectively evaluated 32 dogs which underwent CT ex-aminations and blood pressure measurements on the same day, to determine whether CT-derived abdominal aortic diameter ratios (versus the caudal vena cava [Ao/CVC] and the first lumbar vertebra [Ao/L1]) differed between hypertensive and normotensive dogs. Neither Ao/CVC nor Ao/L1 ratio showed any such significant difference (P=0.393 or P=0.229). We concluded that CT-derived abdominal aortic ratios demonstrated no utility for blood pressure assessments in this study population, an inconsistency with previously reported ultrasonographic findings. Our results may reflect the inappropriateness of CT as an imaging modality, or aortic diameter as an index, for assessing hypertension in dogs. Further large-scale studies are needed to address this question.