Aim of the study was to evaluate the analgesic effects of continuous femoral nerve block (CPNB), with ropivacaine, in dogs undergoing tibial plateau leveling osteotomy with those obtained using parenteral morphine. After inducing general anaesthesia, the dogs received morphine or lumbo-sacral plexus block with the aid of a nerve locator. A stimulated catheter was inserted into the fascial sheath around femoral nerve and, after surgery, connected to a disposable elastomeric pumps for CPNB. Postoperative pain was evaluated using two pain scale. We concluded that the use of elastomeric disposable pumps for CPNB in dog was an effective technique.