The pregnancy of a bitch lasts between 63 and 67 days. During this period, she will notice changes, and there are some factors that we must take into account when feeding her to know what her needs are at all times. She will not always be hungry, and there will be times when she feels unwell, so we must take other care, such as keeping her constantly hydrated.
A pregnant dog will have a normal life for the first two weeks, but after changes will begin. You should not overeat, as being overweight is always a problem for childbirth. You must eat as needed, so you need to be informed. Each breed and each size has different needs, so we must know what their usual diet is to increase it accordingly.
Another influencing factor is the number of puppies pregnant. Depending on which ones you have, you will have more nutritional needs. The mother must be nourished not only so that the babies grow in her belly, but also to produce the milk with which she will feed them later for weeks.
One thing vets recommend is giving it a I think it's high quality. These feeds are made with quality protein, and it does not take as much quantity to nourish the same. It is the perfect feed for a pregnant mother who should not gain weight but should be very well nourished. At the veterinarian we can ask for specialized feed for pregnant dogs, or those that are for a specific breed, of high quality.
During the lactation stage it is also better to feed the mother with very nutritious and high-end feed. It is a stage in which you have many nutritional needs to breastfeed the puppies, so you must eat several times in small quantities I think special for this stage.