Isn't it obvious when someone or something is dead? Actually, no. It isn't. We poke it, watch for movement, but to really be certain, we have to wait for rigor mortis or even the odor of decay.
Not just anybody can pronounce a person "dead." In fact, "death" requires medical diagnosis by an M.D. (in other words, a person with roughly 11 years of training) or, depending on the jurisdiction and the details of the death, a paramedic or a registered nurse. Even so, medical professionals occasionally make mistakes, declaring people dead who really aren't. If a person is hypothermic, or has taken barbiturates, they may appear to be dead on examination. There are certainly reported cases of humans waking up in the morgue or on the embalmer's table, and it is a deep fear of being mistaken for dead that drives the invention of caskets with built in alarm systems in case the deceased wakes up underground.
Could this also happen with our companion animals? Could we mistake them for dead, when they really aren't? Particularly if we have chosen to euthanize, which is generally accomplished through an injection of barbiturates? Indeed, yes. It can happen. Take, for example, the case of Mia. Mia was a ten year old Rottweiler whose family, after watching her suffer from a crippling arthritis, decided to have her euthanized. After the vet administered the standard two-injection protocol, Mia's mourning owner took her dead body home. She was placed in the garage overnight, to be buried the next day. Imagine the owner's shock when Mia greeted him at the garage door in the morning. Now, there was much hand-wringing the in pet-media over this case, and many reports of similar not-so-effectively euthanized dogs, and the obvious question: How do we know this doesn't happen all the time? Usually, an animal's body is placed into a freezer just after being euthanized-until the scheduled pick up from the crematory service (usually once a week, which is too infrequent just to leave bodies lying around). So, really we would never know. Which may make your hair stand on end just a bit.
Reporting on the story of Mia, veterinarian and journalist Patty Kuhly recommended the following checklist to make sure your animal is really, truly dead:
1) Absence of a pulse (by manual palpation).
2) Absence of a heartbeat (via stethoscope).
3) The absence of respiratory movements.
4) A change in coloration of the gums from pink to grayish (pallor mortis)
5) The onset or rigor mortis, in which the limbs become stiff (which can take between 10 minutes and several hours).
We might add several more fail-safe indicators: algor mortis, which is the gradual cooling of the body following death; livor mortis, or a settling of blood in the lower part of the body, and, of course, decomposition and the accompanying smell of decay.
In contrast to humans, anyone can declare an animal dead, with or without adequate evidence. There are no death certificates to fill out and sign, no tests to be administered. The movie Food, Inc. has some incredible footage of cows being "killed" and then moving down the slaughter line, being sliced open from anus to throat, then having their skin boiled off. There must be considerable confusion about death, because the slaughterhouses and the USDA consider these animals dead, after the initial bolt-gun to the brain. Yet the way these carcasses writhe and struggle, one might mistake them for alive, or at least alive-enough.
One of the worst offences we commit against animals is our nonchalance toward death. We don't worry enough about whether our killing has been skillful and whether an animal is really dead before we do stuff to its body. If we must kill animals, more careful attention killing them well is in order.