Animal euthanasia in the context of Félicette

An animal shelter or pound is a place where stray, lost, abandoned or surrendered animals – mostly dogs and cats – are housed. The word "pound" has its origins in the animal pounds of agricultural communities, where stray livestock would be penned or impounded until they were claimed by their owners.

While no-kill shelters exist, it is sometimes policy to euthanize animals that are not claimed quickly enough by a previous or new owner. In Europe, of the 30 countries included in a survey, all but six (Austria, the Czech Republic, Germany, Greece, Italy and Poland) permitted euthanizing non-adopted animals.

In some countries, there is an overpopulation of pets such as cats, dogs, and exotic animals. In the United States, six to eight million animals are brought to shelters each year, of which an estimated three to four million are subsequently euthanized, including 2.7 million considered healthy and adoptable. Euthanasia numbers have declined since the 1970s, when U.S. shelters euthanized an estimated 12 to 20 million animals. Most humane societies, animal shelters, and rescue groups urge animal caregivers to have their animals spayed or neutered to prevent the births of unwanted and accidental litters that could contribute to this dynamic.

Pentobarbital (US) or pentobarbitone (British and Australian) is a short-acting barbiturate typically used as a sedative, a preanesthetic, and to control convulsions in emergencies. It can also be used for short-term treatment of insomnia but has been largely replaced by the benzodiazepine family of drugs.

In high doses, pentobarbital causes death by respiratory arrest. It is frequently used for veterinary euthanasia, and is used by some US states and the United States federal government for executions of convicted criminals by lethal injection. In some countries and states, it is also used for physician-assisted suicide.