Dogs by instinct are very social animals. When in the wild, dogs run together with other dogs as members of a "pack." Over many, many years dogs were gradually domesticated and came to rely on people for care and companionship. You could say - people became the dog's "pack members." When a dog is kept alone outside and never allowed inside with the rest of the pack members, behavioral problems will develop and the dog's safety and health jeopardized.
Most of the behavioral problems stem from boredom and lack of human companionship. Chronic barking, digging, licking of feet, legs and underside, running away, and eating foreign debris are all examples of common problems which occur when a dog is kept entirely outside. Everyday, Humane Societies like ours receive countless numbers of stray dogs which have wandered away from their yards. They also receive dogs relinquished by their owners because of behavioral problems caused by neglect. A good number of these dogs must be euthanized because we cannot place animals with such severe behavioral problems.
Generally, an owner that keeps their dog inside is more observant of that dog, therefore, being more in tune with their dog's health, temperament, and whereabouts. A dog kept strictly outside is more prone to medical problems. These dogs are at a much greater risk for heartworm disease in the summer because they are constantly exposed to mosquitoes. They are at a greater risk for parasitic infection such as fleas, tapeworm, whipworm, and roundworm. There is also the potential to pick up such diseases as rabies, parvo and distemper because they can come into contact with unvaccinated stray or wild animals. Digging in soil exposes the dog to fungal infections. Outside-only dogs are also more prone to ear problems such as fly bites, ear mites and infection.
Extreme temperatures also affect the dog's health. Dogs that are kept outside in the extreme cold can experience hypothermia which can lead to frost bite, upper respiratory infection, dehydration (if no water is available or frozen), stress which causes the dog's organs to work harder, and even death. Exposure to extreme heat can cause hyperthermia which can lead to dehydration, weight loss (due to loss of appetite), stress and death. Dogs kept outside are also exposed to the wind and rain which leads to upper respiratory infections such as kennel cough and pneumonia. In addition, moist environments can cause skin infections, hair loss and fungal infections.
Dogs that are kept outside all the time may cause harm to themselves when trying to escape the yard. Broken bones, abrasions, mouth injuries, intestinal problems and infection can all occur when trying to break a chain or jump over, chew through or dig under a fence. If the dog does make it out of the fence, they face other dangers such as being hit by a vehicle, poisoned, or harmed by another animal or human. They may also be stolen or picked up and taken to a local animal control facility. Or they may just disappear.
So, you see how the controlled environment of an inside dog helps prevent and improve the dog's health, well-being and lifespan. Face it, we as humans domesticated the canine to work along side us and be a companion to us. They now rely on us to provide for them, protect them and be a friend to them. Keep your dog inside where he/she can be a part of your family - their "pack."