Many friends like to keep large dogs. Large dogs may have a greater deterrent effect on intruders, but they will be more expensive to buy and keep. Large dogs eat a lot, excrete a lot, and exercise a lot, obviously not suitable for living in an apartment block in the city center. Young children and the elderly may be unable to control large dogs, although most large dogs have a very tame temperament. Small dogs are slender and require less exercise, making them more suitable for families with older adults and children, but small dogs are more prone to injury and are often more sensitive, agitated and barked.

Puppies are usually chosen. Puppies who grow up in the family will establish a strong mutual trust relationship with their owners, making it easier to train at home. Watching puppies grow day by day is also an irreplaceable joy. But puppies take a lot of time and energy for their owners to grow up, and puppies that are too lively for the elderly may be a burden. Adult dogs usually maintain an attitude of attachment to the previous owner, and also maintain some previous living habits, which are not easy to change, but for an owner with insufficient energy, adult dogs are relatively easy to worry about. Usually, dogs that have been strayed will cherish the warmth of their new home more, so going to a stray dog shelter is also a good choice.

Usually bitches are docile and more attached to their owners, but there are two estrus periods each year during which the bitches can be unstable in temperament and soil the floor of the home. If you give birth to a female dog, caring for her is also time-consuming and labor-intensive, although having a litter of puppies can be a lot of fun. Male dogs are better physically and learn better, but usually have a slightly heavier body odor, are relatively difficult to train, and have a strong dominance instinct that may prompt him to fight other male dogs.

Mixed or mongrel often conjures images of sickness or bad, but in reality the word only means that the dog is born of unknown origin or that the parents are of different breeds, and their strain is not recognized by the Purebred Dog Association and cannot be obtained by blood. Certificate, usually also can not participate in official competitions. But otherwise, mixed-breed dogs are far less likely to develop genetic diseases than purebred dogs, and are generally healthier and more active. If you're not a dog owner, or you want your dog to compete, there's no particular difference between a mixed-breed dog and a purebred dog.