Sodium Pentobarbital, when given by itself with the IV route of administration offers completely approved, painless, and humane death.  However, it is Paws at Peace standard practice to give other medications for sedation, pain control, anesthesia, and reduced anxiety, prior to Sodium Pentobarbital.  Very nearly 100% of veterinarians use Sodium Pentobarbital for euthanasia.  However,  the difference between a peaceful euthanasia and a stormy pet passage usually comes down to training and skill.  With special training and education veterinarians can  use techniques and supplemental drugs to maximize peace and comfort experienced  by the pet as they are passing.  These drugs may be given subcutaneously, intramuscularly, intravenously, or in special cases (like reptiles and exotic pets) inhaled.   Some of the examples of drugs we use are: ketamine, tiletamine, diazapam, midazolam, zolazapam, butorphanol, xylazine, medetomidine, acepromazine, and propofol.