Get a Dog House
You should have a dog house for every dog in your home, even if you have indoor pets. This provides shelter from the hot summer sun, as well as warmth in the autumn and winter months. If you do not have a dog house yet, invest in one before the weather starts to turn too cold. Make sure it is large enough to support your pet's current and future size, but not so large that it will not be able to keep temperatures up in the winter.
Know Your Dog's Limits
Every dog has a limit to the amount of cold he can take. This will depend on the size of the dog, the length of the hair, the breed of the dog, and the amount of time he spends outdoors. A shorthair dog is likely to get colder faster than a dog with thick or long hair. A dog that is used to living outdoors may be more tolerant of temperature changes than a dog that stays inside most of the time. Watch for changes in behavior with your dog to see if he is acting lethargic, unenergetic, or out of the ordinary while outdoors. If so, you may need to find other ways to keep your pet warm.
Invest in Dog Clothes
If your dog is a small breed, a shorthair breed, or a breed that did not originate in a cold environment, you may need to invest in coats and sweaters for your furry friend. It may take you some time to train your pet to wear clothing, but that added layer of warmth will come in handy when the winter starts to settle in. Get clothes that fit the size and shape of your dog, paying close attention to the materials they are made from. Sweaters have a tendency to snag on twigs outdoors and are not ideal for dogs that spend most of their time outside.
Bring Your Dog Indoors
If it is too cold outside or your dog simply cannot stand up to prolonged exposure to the elements, bring him inside. If you cannot bring your dog into the home completely, consider getting a shed with a heater or bringing the dog into the garage. If you have a farm, you may be able to let the dog sleep in the barn with other livestock, assuming he can get along with other animals. Do what you can to keep your pet as safe and comfortable as possible.