A puppy incubator, or puppy box, is useful to help puppies get off to a good start in the first few hours of their lives. According to the American Kennel Club, puppies are unable to regulate their own body temperatures in the first few days after birth. Newborn puppies need to be kept in a moist environment with a steady temperature close to 95 degrees. In normal situations, the body warmth of the mother provides these needs. In situations where keeping the puppy close to the mother's body is not possible, such as the first puppy in a litter, an incubator may be useful.
Line a wooden or cardboard box with Styrofoam insulation. You can build such a box out of plywood and nails or glue. The size of the puppies anticipated will determine the size of the puppy incubator. A dog owner whelping Pomeranians, for example, might need a 12-inch by 12-inch by 6- or 8-inch deep box. Someone whelping Great Danes could use a box twice that size. The box needs to have the capacity to contain the entire litter under worst conditions. The top of the box and one side should be removable to allow access to the puppies for both the owner and the mother dog.
Place a controllable heating pad in the box, wrapped in a towel. Control is vital. The AKC says the ideal temperature for puppies during their first five weeks of life is between 85 and 90 degrees F. Monitor a thermometer placed in the box to maintain the proper temperatures.
Place a small dish of water in the box. Puppies won't be drinking water at this time, but the humidity created by the water dish next to the heat pad is important. Because the skin of newborn puppies is not fully developed, it can dehydrate quickly. The ideal relative humidity for the incubator is 65 percent. Place a humidity gauge in the box and monitor it closely while the puppies are in the box.