It is widely accepted that 9.6 million animals are euthanized annually in the United States.
'Euthanization' is an inaccurate term since it is defined as 'mercy-killing', to be administered only to terminally ill or injured animals.  Most cats and dogs being put to sleep in shelters are healthy, loving, adoptable animals, and  what is happening would be more aptly described as a 'cull' or 'slaughter'.  The situation has become catastrophic and begs investigation, oversight and compassionate solutions.  33,000 animals being killed every day is not acceptable in a country that calls itself humane.  Humans are not being responsible and animals are paying the price.