After birth, puppies should gain 1 to 1.5 grams a day for each pound of anticipated adult weight, and should double their birth weights in 10 to 12 days. The anticipated adult weight is the weight of the dam. So if the dam weighs 30 pounds (13.6 kg), the puppies should gain 30 to 45 grams per day. (One ounce equals 28.35 grams.) A steady gain in weight is the best indicator that a puppy is doing well.
It is important to weigh each puppy at birth and 12 hours later on a scale that measures grams or ounces. You will need a scale that measures fine increments, because, initially, the gains are such small amounts. Then weigh each pup daily for the first two weeks and every three days thereafter until the puppies are 1 month old. Failure to gain weight is a cause for immediate concern. Notify your veterinarian.
When several puppies in the litter are not gaining at the expected rate, consider a maternal factor such as failure to produce enough milk (see Agalactia). A nursing dam needs two to three times more nutrition than a typical adult dog. If the mother is not getting enough calories, her milk supply will be inadequate to support a large litter.
When to Supplement
Puppies who gain weight steadily during the first seven days of life are in no danger. Puppies who lose some weight, but not more than 10 percent of their birth weight, for the first 48 hours of life and then begin to gain should be watched closely. Puppies who lose 10 percent or more of their birth weight in the first 48 hours and are not gaining by 72 hours are in trouble. Start supplemental feedings at once.
If a puppy is 25 percent below the average weight of his littermates at birth, you can expect a high likelihood of mortality unless the puppy is hand fed. If possible, allow the pup to nurse for the first 24 hours to receive colostrum. Then place him in a homemade incubator and raise him by hand. Alternatively you can supplement his nursing with hand feedings, but keep him with the litter – always checking that he is not being shoved away from the dam by larger pups. As soon as his weight approaches that of his littermates, he can be returned to the nest. Many immature puppies can be saved if supplemental feedings are started before they begin to fail.