Chronic intraperitoneal administration of fluids in rats

A simple method for continuous long-term intraperitoneal administration in rats was devised. Polyethylene tubing was inserted into the peritoneal cavity through an incision in the abdominal wall just below the rib cage. The other end of the catheter was then guided subcutaneously toward an incision located in the back of the neck. The external opening of the catheter was blocked with a small piece of stainless steel wire. The indwelling intraperitoneal catheter permitted instillation of various solutions in rats four times daily for up to 94 consecutive days without apparent stress or pain on the treated animals. The catheter remained patent for the duration of the study in 39 of 60 (65%) rats.