Computed Tomographic Assessment of the Main Abdominal Vessels in Dogs

Computed tomographic (CT) characterisation of abdominal vessels is poorly studied. The objectives of this retrospective study were to assess during growth, by CT angiography, the evolution of the aorta (Ao), caudal vena cava (CVC), portal vein (PV), length of the second lumbar vertebra (L2) and different ratios between these structures; and to determine the influence of weight and age on the vessels' sizes and ratios. The first group included six beagles scanned every month from 4 to 12 months old, then every 3 months up to 24 months old. The second group included 26 dogs of different breeds and weights that were considered haemodynamically normal. These dogs were divided into three weight intervals: < 10, 10-30 and > 30 kg. The measurements were repeated three times by three operators. The diameter of the Ao, CVC and PV, the aortic length and the L2 length increased up to 7 months. Similarly, the different ratios, such as CVC/Ao, VP/Ao, Ao/L2 and CVC/L2, were variable up to 7 months old and became stable after 7 months. The diameter of the Ao, CVC and PV, the previously cited ratios and L2 length were variable between weight intervals but stable within one interval. The adult vascular standards and ratios published in the literature should not be used in medium-size dogs younger than 7 months old. As variability is observed between the weight intervals, measurements should be used with care in very small or very large dogs.