Animal protection advocates call attention to the darling overpopulation "crisis" in the United States. According to the Humane Commonality of the United States, 3-4 million dogs and cats are euthanized each annual accounting Pet Supplies period in the countrified and many more are confined to cages in shelters. This crisis is concocted by nonneutered chase (spayed/castrated) reproducing and people intentionally breeding animals.

In the United Kingdom, the Pets4Homes Rescue website was the first to bid an online service, uniting multiplied of the rehoming centres and animal welfare groups using an easy to convenience blog style system