Pre-surgical care typically involves, at minimum, pre-operative weighing and a general evaluation of health. Animals that do not appear healthy should not be utilized in a surgical procedure and should be brought to the attention of a DLAM veterinarian.

It is generally not necessary to preoperatively fast mice or rats unless gastrointestinal surgery is being performed, as these species cannot vomit. For other animals, consult veterinary staff to determine the appropriate fasting period for prevention of vomiting, aspiration, and problems associated with a distended intestinal tract.