Common Vascular Changes in the Jugular Vein of Saline Controls in Continuous Infusion Studies in the Beagle Dog

Abstract

This review was performed to assess the nature and incidence of procedure-related background changes in control dogs receiving saline by continuous infusion, and to compare them with data from a similar review previously done in Cynomolgus monkeys. Data were collected from 14 dog studies performed over an 8-year period (i.e., 86 animals in total). The review was restricted to lesions at the injection site, in the lungs and at the catheter's entry point. The most frequently seen changes were endothelial hyperplasia (67.4%) and intimal thickening at the injection site (80.2%) and interstitial pneumonitis in the lungs (52.6%), all seen at a higher incidence in dogs than in primates. Although incidences of thrombosis at the injection site were similar in both dogs (27.9%) and monkeys (34.1%), the incidences of thromboemboli and secondary infarction in the lungs were much higher in dogs. This suggests that dogs have a greater propensity to thrombus formation and fragmentation at the injection site. However the fact that the femoral vein is used in monkeys and the jugular vein in dogs may explain this difference. The larger diameter of the jugular vein in the dog with its greater turbulence of blood flow possibly predisposes to fragmentation and dispersal of thrombi.