If you live in the frigid north, a heated dog house can go a long way towards keeping your dog warm and happy. This is especially true for short-haired breeds such as Daschunds, Greyhounds, German Short-Haired Pointers, and Whippets. Such dogs don't have a thick woolly coat and may need a little help staying warm in the cold weather. Older dogs also feel the cold more since their metabolism and general fitness isn't what it used to be (kind of like people).
In terms of heating a dog house, there are several options. The first is to purchase a standalone heater/AC unit such as the PETCool Therm-ASSURE system. Although this unit will set you back $400-$500, it automatically maintains a comfortable and safe year-round temperature for your pet. It also doubles as a de-humidifier to keep mold and mildew at bay.
Another option is to buy a heated kennel mat. You just put it on the floor of the dog house and plug it in. This is an inexpensive and generally effective way to warm your pet although some owners may be a bit nervous about their dog sleeping directly on an electric device with a cord running from it. Most mats have a metal safety coil around the cord so chewing through the cord "should" not be a safety issue.
A third means of heating a dog house is with a heater box -- basically a metal box with a light bulb or ceramic emitter inside. The box mounts in an upper corner of the dog house so as to not impinge on your pet's sleeping space. The heating unit will stay at a comfortable temperature when the outside temperature is below freezing. A separate thermostat can be purchased to maintain a fairly constant temperature.
In addition to supplying an external heat source, there are several construction features that should be employed when building a cold weather dog house: 1) build the dog house off the ground, 2) build the house large enough for your dog to comfortably turn around and to stretch out but not so large that it own body heat can not keep the house warm and 3) insulate the floor, walls, and roof of the house, 4) cover the doorway with a flap of vinyl, burlap, or carpet, 5) install an interior wind break wall so your dog can sleep in a more protected area of the house.
