The dog is the most popular domesticated animal on earth. Humans originally kept dogs to help them hunt. Domesticated from the gray wolf about fifteen thousand years ago, dogs played an important role in early human settlements. In addition to hunting, they helped pull heavy loads and were expert herders. It wasn't until they became a companion animal that buying a pet dog became popular.

Based on a recent survey, there are more than 400 million dogs in the world. Alone in the United States, there are more than 75 million people who own this loyal friend. Their popularity as pets can be ascertained from the fact there are more animal lovers in the United States that have dogs as their pet animals rather than the cats.

The popularity of the domesticated dog has encouraged cross breeding. Though the American Kennel Club only recognizes 157 distinct dog breeds, there are several thousand if we include mixed breeds. As you might expect, this can make selecting the right dog a chore.

The single most important consideration is the recipient of the dog. A single person often looks for different characteristics for their pet dog than families. Generally, a single person is more likely to select a bigger, more aggressive animal than parents who look for a dog that is good with children.

Dogs such as Rottweiler, Pi Bulls and German Sheppard are not recommended for houses with kids as they are more aggressive and not very kid friendly. On the other hand, small sized dogs such as Cocker Spaniels, Beagles and Golden Retrievers are in the category of friendly dogs and are suitable for families with kids.

Some dogs require more maintenance than others. The Poodle, for example, requires almost daily grooming. Its coat must be brushed for at least twenty minutes each day, especially if the dog is allowed outdoors. Other dogs like the Siberian Husky are prone to nonstop shedding in the spring and summer months. So, if you can't handle daily grooming or big white clumps of fur, it's best to steer clear of these breeds.

Diet also needs to be considered as the bigger the dog, the more it will eat. A St. Bernard or a Great Dane requires an enormous amount of food to keep their big bodies going. Feeding a larger dog can be very expensive compared to a smaller breed.

Like humans, the more intelligent the dog is, the less time it will take it to learn things and get friendly with people around the house. This feature may also be given consideration when selecting a dog as it may save you good amount of time in training the dog. Some intelligent breeds of dogs include Poodles and Border Collies, which are much preferred choices as household pets.

Most children love dogs but rarely enjoy walking them. For many children, walking the family pet is a chore and generally, the more energetic a dog is, the more needs to be walked. According to experts pugs, bulldogs and French bulldogs have noticeably lower activity levels than other breeds and are said to be great with children.