A pet is an animal kept for companionship and enjoyment, based on the human-animal bond. Pet animals are generally considered to be different than livestock, laboratory animals, working animals or sport animals, or any animal that is kept for meat, work, or other economic reasons. However, there is probably some person somewhere who has kept one of those "practical" animals purely for companionship! There are many cultural differences in attitudes towards keeping animals as pets. On one extreme, there are cultures in which it is considered that animals should not have food and human resources "wasted" on them, and keeping an animal without using it for food or work is considered to be a wrongful practice. Some societies have cultural taboos against certain animals or types of animal. At another extreme, there are animal rights activists who feel that imposing human dominance on an animal is disrespectful, and restricting the freedom of an animal by keeping it as a pet is a wrongful practice. Almost everyone would agree that only certain types of animals are suited to being pets, and, in fact, many countries and districts actually impose legal restrictions on pet keeping.
Tamed animals that have been selectively-bred for generations are called domesticated animals. Whether tame or captive, pet animals bring pleasure when they are healthy and thriving. Not all animals are suitable for being kept as pets.
Some animals can be tamed to live in a household as a companion. People who live in rural areas with land available to keep larger pets may make pets of livestock, and many individual animals of kinds that can be used for food or wool or milk, are, in some families, country pets. Other animals, whether kept indoors or out, have little interaction with their human companions, but, from their owners' point of view, make a good pet because of the pleasure that the animal's presence brings them. Keeping such pets hinges on being able to provide a proper environment.
People sometimes treat their pets much like children, especially when they do not have children, or their own have left home. A person living alone may have a pet to combat loneliness.
While in theory any animal might be a pet, in practice, only a small number of species of mammals, especially dogs and cats, and other small animals, such as birds and fish are practical for several reasons. Aside from the obvious (eg, elephants being unsuited for small apartments), which species are suited for being pets is less easy to understand.
Dogs and cats are the most common types of pets, thought they have very different character traits. Dogs, like humans, are highly social, and the dog is seen as a loyal companion, who is more amenable to be trained, whereas a cat is more independent, and as such are not generally trained in the way that dogs are. Both can be very intelligent and can form incredibly strong bonds with humans.
Koko the gorilla is one of few examples of a non-human animal which has had an its own particular pet. She requested a cat. Koko's first pet was a kitten named All Ball, to which she was reported to be quite attached and mourned for several days after the cat escaped and was killed by a car.
A pet must either be so small or easily controlled that its own behavioural tendencies are irrelevant, or the animal must be actually domesticable. Examples of the former are such things as fish (eg, small ones, even including carnivorous ones such as piranha), or small reptiles.
Animals such as reptiles are typically considered exotic pets. Some are quite exotic by any definition. The glofish, a genetically modified zebrafish with a bright red fluorescent color, is the first genetically modified (GM) animal to be engineered as a pet.
Some animal welfare organisations have proposed that the term "companion animal" be used instead of "pet".
The term "pet" may also be applied to humans, usually in an endearing way by a lover, significant other, or partner. Calling another person a pet, though, can just as easily be considered an insult (see "plaything").
In veterinary medicine, dogs and cats are often considered "common" pets, while all other animals are grouped into either "farm animals" (such as horses, cows, sheep) and "exotics" (including pocket pets, birds, reptiles).
Some animal rights activists object to the idea of holding a pet. They believe that holding an animal against its will is violating it as an individual being.
Many cities and towns have local ordinances limiting the number of pets a person may have, and may also restrict or forbid certain pets (such as fowl or exotics).
Animal protection advocates try to call attention to the "pet overpopulation crisis" in the United States. According to the Humane Society of the United States, 3-4 million dogs and cats are euthanized each year in the country and many more are confined to cages in shelters because there are many more animals being born than there are homes. This crisis is created by non-spayed/neutered animals reproducing and people intentionally breeding animals. In an average year a fertile cat can produce three litters of kittens, with up to 4 to 6 kittens in each litter. Based on these numbers, one female cat and her offspring could produce up to 420,000 cats over a seven year period if not spayed or neutered. There are also major overpopulation problems with other pet species, such as birds and rabbits. Local humane societies, SPCA's and other animal protection organizations urge people to spay or neuter their pets and to adopt animals from shelters instead of purchasing them from breeders or pet stores.
Pets can pass a number of parasites, bacteria, and viruses to humans.[1] The following guidance may avoid these infections:[1]