The Facts
Having portraits made of a pet is the equivalent of having them immortalized on film. For high-quality photos, most people turn to professional pet photographers. These pet photographers usually offer a choice: studio shots in their professional photography studio or location shots at the client's home.
History
Although pet photography has been around for as long as personal cameras have, the movement from hobby to profession has happened within the last 20 years or so. In 1996, The Humane Society began using pet photography as an advertising and marketing technique by endorsing the "All American" Pet Photo Contest. Pet photography has also been featured in major films. A Google search for "pet photography" will bring up several pages of professional pet photographers advertising their wares.
Function
People use pet photography for a variety of reasons. Some put the photos on their desks or walls. Others take--or have made--a preliminary photo, which is then used as a model for a painted portrait. If a dog breeder has a pedigreed dog for breeding, he has a professional picture made for advertising that dog. Kennels regularly use professional pet photography to advertise themselves and their services.