This permits the veterinarian to allow sufficient time and staff assistance to properly care for the patient. The other advantage to scheduling in advance is patient preparation. In most instances, we request a patient undergoing general anesthesia to fast a minimum of 12 hours before admission. In essence, this means taking up the dog's food the night before the procedure is to be done. An empty stomach reduces the likelihood that the dog will vomit during the procedure.
Vomiting is quite dangerous to the anesthetized patient.
Stomach contents can be inhaled through the trachea into the lungs producing aspiration pneumonia, a potentially fatal complication. The proper use of an endotracheal breathing tube during inhalation anesthesia also helps prevent aspiration from ocurring. I recommend taking away food only from the patient, and continuing to allow free access to water during the hours preceeding the anesthetic episode. Another point of concern for owners is how long their pet will have to stay in the hospital following the anesthetic procedure. This is usually a issue of each veterinarian's policies and preferences.