Question of the Day

A pentobarbital overdose causes global, extreme central nervous system depression. This rapidly and painlessly depresses all the vital functions of the CNS, resulting in loss of consciousness in seconds and death within minutes.

It is a barbiturate that is given at a very high dose for euthanasia. Other barbiturates are used for anesthesia (e.g., thiopental) or seizure-control (e.g., phenobarbital). 

When giving barbiturates to induce anesthesia, we give a much lower dose and give it slowly to avoid respiratory depression (and have oxygen support nearby, if needed).

The Humane Society of the U.S. has put together a helpful Euthanasia Manual. 

The AVMA has complete Euthanasia Guidelines.