You can make a satisfactory incubator by dividing a cardboard box into separate compartments, one for each puppy. The compartments are important because orphaned puppies tend to suckle each other’s ears, tails, and genitalia, which can cause problems. It goes on for the first three weeks. (If the puppies are nursed using a bottle and not a stomach tube, this may not happen.) After three weeks, the puppies should be put together for socialization and to establish normal behavior patterns.
The temperature in the incubator is of critical importance, since it provides the warmth that would have been provided by the mother. Place a thermometer in the incubator to monitor the surface temperature. Keep the incubator at 85° to 90°F (29.4°C to 32.2°C) for the first week. During the second week, reduce it to 85°F to 80°F (29.4°C to 26.7°C). Thereafter, gradually decrease the temperature to 75°F (23.9°C) by the end of the fourth week.
The temperature in the incubator will be the same as the room temperature if there are no drafts and you insulate the floor beneath the incubator with heavy padding. If the incubator and room temperature cannot be maintained with your existing heating system, provide additional heat using infrared heat lights or electric heaters. Avoid focusing heat directly on the puppies.
Electric heating pads can be used as a heat source, but are not as safe as heating the room. Puppies can become severely dehydrated or burned by continuous exposure to heating pads. If used, they should be heavily padded and should cover only one side of the box and one half the floor. This allows the puppies to escape from the heat if they become too hot. Cover the pad with a waterproof material such as plastic or rubber.
On the floor of the incubator place a baby diaper that can be replaced when it gets wet or soiled. This also provides a way to easily check the appearance of each puppy’s stool, which is an excellent indicator of overfeeding.
Maintain the humidity of the room at about 55 percent to prevent dry skin and dehydration.