02/28/2012 04:14 pm ET

World Spay Day 2012: Campaign Hopes To Save Animals Worldwide

Will you help save animal lives on World Spay Day?

Held on the last Tuesday of every February, World Spay Day is part of a campaign to promote animal sterilization and reduce overpopulation.

The Humane Society of the United States says spaying or neutering is "a proven way to save the lives of companion animals, feral cats, and street dogs who might otherwise be put down in a shelter or killed on the street."

Despite the presence of millions of feral cats and street dogs in the U.S., 78 percent of owned dogs and 88 percent of owned cats in America are spayed or neutered, according to 2011 statistics from The Humane Society.

The Humane Society of the United States estimates that half of the 6-8 million cats and dogs that enter shelters each year are euthanized. A single unsterilized female cat and the resulting offspring "can create 420,000 cats in just seven years," according to PETA.

The Humane Society of the United States began World Spay Day in 1995. The day is now reportedly observed across 46 countries, According to AP.

For a list of World Spay Day events and information on how to have your pet spayed or neutered, visit the The Humane Society of the United States' website.

Below, learn about the fate of some of the world's stray dogs.

Stray Dogs