Importance of Weight Gain
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. 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.