If a puppy is immature, weak, or fading, early treatment is imperative. New pup- pies are extremely fragile and can die quickly. Treatment involves slow warming to restore body temperature, oral fluids to correct dehydration, and supplemental feedings to provide calories.
A chilled puppy should be warmed gradually. Rapid warming using, for example, a heating pad, causes the blood vessels in the skin to dilate, increasing heat loss, expending more calories, and creating a greater need for oxygen. This harms rather than helps. However, if the puppy’s rectal temperature is below 90°F (32.2°C), rapid warming under veterinary supervision may be required as a life-saving procedure.
The best way to warm a puppy gradually is to tuck him down next to your skin beneath a sweater or jacket and let your own warmth seep into the puppy. If the puppy’s rectal temperature is below 94°F (34.4°C), warming will take two to three hours.
Chilled puppies are usually hypoglycemic and dehydrated. Correct mild to moderate dehydration by giving a warmed glucose-electrolyte solution such as Pedialyte, which can be purchased at drug stores and large grocery stores. Give l cc per ounce (28 g) of body weight every hour by eyedropper or baby nurser and warm slowly until the puppy is wiggling about. If a commercial solution is not available, as a temporary expedient you can substitute a solution of 1 teaspoon (8 g) of granulated sugar to 1 ounce (30 ml) of water. Severe dehydration, in which the puppy is too weak to nurse, should be treated by a veterinarian.
Never allow a cold puppy to nurse or receive formula. Never give chilled or cold formula to any puppy. When chilled, the stomach and small intestines will not digest or absorb milk. The puppy will bloat and perhaps vomit.
Once the puppy is warm and wiggling about, begin supplemental feedings to restore liver glycogen and supply calories, as described in Raising Puppies by Hand. If the puppy is immature, he will not be able to compete successfully with his littermates for milk and should be placed in a homemade incubator and raised by hand.