Every year, between 6 and 8 million dogs and cats enter US animal shelters.[107] The Humane Society of the United States (HSUS) estimates that approximately 3 to 4 million of those dogs and cats are euthanized yearly in the United States.[108] However, the percentage of dogs in US animal shelters that are eventually adopted and removed from the shelters by their new legal owners has increased since the mid-1990s from around 25% to a 2012 average of 40% among reporting shelters[109] (and many shelters reporting 60–75%).[110]BiologyLateral view of...
