Chronic intravenous infusion in the rat: a nonsurgical approach.

A rapid, simplified technique of intravenous catheterization of the unanesthetized rat was developed for continuous infusion. A 19-gauge thin-walled needle was inserted percutaneously into the dilated tail vein, and polyethylene tubing was advanced through the needle into the vein. The catheter was protected by wire mesh electrical sheathing taped securely to the tail. This approach eliminated the need for anesthesia and surgery which were traumatic to the animal and time consuming for the investigator. This method was used successfully in 32 rats given continous infusion for up to 5 days.