Recommendations state that before breeding, the female dog needs to be in good condition. This includes nutritional status, up-to-date vaccinations, and any parasiticide agents administered (endo- and exo-parasiticides). A good body condition score (BCS) and muscle condition score are required. Female dogs that are overweight could present with dystocia during birth.
Obesity, as demonstrated in humans, can also affect fertility. Maintaining female dogs during the first six weeks of pregnancy on their original adult diet is possible, provided the diet is of good quality and is not lacking in any specific nutrients. During the final trimester, the female dog will need to be switched to a growth/puppy diet. Large-breed puppy diets are not recommended even for large-breed female dogs. These dogs will require a puppy growth diet for dogs under 25 kgs. This is due to large breed puppy diets having a decreased level of energy, which is especially required by the female dog in the last three weeks of pregnancy. The female dogs weight should increase to approximately 25% more than at the time of breeding; however, this does depend on the number in the litter. During this stage, more frequent feeding may be required due to a decrease in the quantity of diet consumed at each meal. If the female dog is having difficulty consuming adequate calories ad libitum feeding should be introduced. Fresh water must be made available at all times.
The feeding of female dogs during pregnancy does differ from that of other dogs. Female dogs increase food intake soon after conception; which continues to increase with the duration of gestation (pregnancy) . During the first third of pregnancy, the female dog will lay down fat reserves, which will be used towards the end of gestation and during lactation (providing milk).
Lactation places huge stresses on the nutritional demands on the female dog. The nutritional demands can increase from 3-6 times that of maintenance. This is dependent upon the number in the litter. The growth diet still needs to be fed free-choice (ad libitum). Large volumes of water will be required and must be available at all times. Peak lactation demands will occur at three to six weeks of age, and further nutritional support of the female dog will be required. Colostrum is vitally important to all mammals, it contains many antibodies from the female dog, aiding in the early immunological status of the puppies. Female dogs sustain a loss of body weight during lactation. Ad libitum feeding during pregnancy will allow for the increase in body tissue that will be metabolized during lactation and by fetal energy demands. The weaning body weight of the female dog should not be less than the body weight at conception.
When nursing, puppies should be vigorous and active. For the first three to four weeks with puppies exclusive feeding from the mother is possible if she is healthy and well-nourished. The expected weight gain of puppies should be 2-4g/day/kg of anticipated adult weight (or at least 10 percent gain per day). Puppies not receiving sufficient milk will cry, become restless or extremely inactive, and fail to achieve the expected weight gain. It should be remembered that littermates differ; and will gain weight at different rates.