According to the American Society for the Prevention of Cruelty to Animals (ASPCA), around 4 million dogs enter shelters every year (ASPCA, n.d.). Many companion animal seekers acquire their new family members from shelters (Weiss, Miller, Mohan-Gibbons, & Vela, 2012). Meanwhile, Pet Food Manufacturers Association (2012) reported that almost 47% of pet owners will relinquishment the ownership of their dogs and turn them to the agents like breeders, pet shops, who can resell puppies or dogs. Some owners explain that with finding a new job, they need to relocate to other states, with different apartments, which does not allow pets.

Without any adoption happened to those pets, they will be crucially euthanized due to the limited space and any other food or financial resources in shelter or any pet adoption organization. Or for other reasons, such as no-kill shelters, non-aggressive breeds, or having a higher likelihood to be adopted pets, shelters will keep those pets until they are adopted (American Veterinary Medical Association, 2002). However, the criteria applied for holding a dog in a shelter for adoption are comprehensively subjective and will consider the characteristics such as breed, age, gender, size, temperament, health, and appearance (Winograd, 2009).