The animal is either over-anesthetized or has lost too much blood during the course of the surgical procedure. Adjust the anesthesia concentration and/or dosage, or choose a more appropriate anesthetic agent.
米inimize blood loss during surgery by careful dissection. Also, try tying off severed vessels with suture, or use electrocautery to keep blood loss to a minimum.
Note: Do not use electrocautery while the catheter is inside the animal. This has the potential to damage the catheter and could render it inoperable.
