Dogs With Tennis Balls

Every year, between 6 and 8 million dogs and cats enter US animal shelters. The Humane Society of the United States (HSUS) estimates that approximately 3 to 4 million dogs and cats are euthanized yearly in shelters across the United States. However, the percentage of dogs in US animal shelters that are eventually adopted and removed from the shelters by their new owners has increased since the mid 1990s from around 25% up to around 60–75% in the mid first decade of the 21st century.
Pets entering the shelters are euthanized in countries all over the world because of the lack of financial provisions to take care of these animals. Most shelters complain of not having enough resources to feed the pets and by being constrained to kill them, as the likelihood for all of them to find an owner is very small. In poor countries, euthanasia is usually violent.