Pregnancy in dogs can be a wonderful time to care for your beloved pet. A pregnant dog experiences changes in her hormones, weight, appetite, and behavior – just like humans.
Gestation is the period from conception to birth and averages from 59 to 63 days for dogs.
During the first few weeks of gestation there are few signs of pregnancy except for a slight gain in weight. Occasionally a female dog may experience morning sickness. This usually happens during the third to fourth week of pregnancy and unless you are particularly attentive, you may not notice it at all. If vomiting occurs feed several small meals spaced throughout the day.
Developing puppies about day 28 are about the size of walnuts in the average size dog. Sometimes the puppies can be detected by gently palpating the abdomen at this time but after day 35 the fetuses are floating in sacs of fluid and can no longer be detected by palpation.
Puppies may be seen on x-rays as early as 38 to 42 days by their skeletal development. X-rays can help determine how many puppies can be expected and are not harmful to the mother or fetuses. X-rays can also distinguish between pregnancy, false pregnancy, and pyometra (infection in the uterus).
By day 40 the nipples begin to darken and enlarge and the belly has increased in size. As birth approaches the breasts enlarge and a milky fluid may be expressed from the nipples. However some female dogs have breast enlargement after a normal heat cycle and some female dogs may also experience a false pregnancy in which she may also express a milky fluid from the nipples.
For more information please see Labor in Dogs.