Euthanization is, very simply, an overdose of an anesthetic. Because of the drug used (Phenobarbital), it is typically painless for the dog. The Phenobarbital is administered using a small needle and directly through the vein. The dog will lose consciousness within a few seconds and, after about 10 seconds, her heart will stop and her brain’s activity will cease.
One of the more painful aspects of euthanasia for the owner is the fact that the electrical activity in the body can continue for several minutes after death. Legs and some facial nerves can twitch while the body triggers the lungs to take a reflexive gasp. After ten minutes, this activity should stop.