How many animals have been abandoned in America?

Maryann Mott for National Geographic News September 7, 2004 reported that some feline experts now estimate 70 million feral cats live in the United States as a consequence of little effort of population control and of the cat's ability to reproduce very fast.

http://news.nationalgeographic.com/news/2004/09/0907_040907_feralcats.html