Because of that, they are characterized by highly flexible spines, deep chest, and big lungs and have very nimble bodies. Non-sporting dogs Are dogs that were previously bred for specific tasks. As times changed, so did their duties and purpose. There is no definite category for these dog breeds except that over the years their function were deemed less important than the general value that they serve whether as pets, entertainers, companions, guardians etc. By that it means that the dog is friendly to both man and other smaller animals and gentle. Companion dogs have a life expectancy of up to 16 years. They weigh, depending on the breed, from 4 to 16 pounds and are prone to ailments that are related to their size. Before adopting a dog for a companionship, it would be well to do a little research regarding health, ailments, and other breed specific issues on health. They tend to be very loyal and dedicated to their owners. For people who can t commit to a lifelong responsibility, a senior dog offers a very ideal pet. Because they have shorter remaining lifespan, their owners don t have to have to turn their old dog away. Finally, adopting a senior dog is a selfless act of love. Make no mistake, though. Small dogs do not always make for behaved dogs. As if to compensate for their small size, some small dogs develop tough dog attitudes. Be prepared to do plenty of obedience training to curb their small dog aggressiveness. Mid-size dogs, on the other hand, are ideal for most kinds of keepers from children, adult to old people. Agree on areas that are off limits to the dog and areas where the dog is allowed. If the dog is not yet trained, do not allow the dog to sit on the furniture or sleep in the bed with people. When limits are not set and the dog is allowed to do as it wants, the dog will attempt to dominate. This is an old pattern of dog behavior that is carried over since the dogs were still in the wild. When you have small children though, it is not wise to have small dogs around a small space. Small dogs are very energetic and highly active creatures that will tend to topple things aside from not being safe to be around little children. Large dogs on the other hand are slower and more placid. If you have the time to get the dog out regularly for walks and exercise, a large dog will fit in nicely even when the space is limited.