During the sixth week of puppy fetal gestation, the skin pigment is developed. The fetal heartbeat can be detected with a stethoscope,
and the fetuses should weigh approximately six grams and measure 45 millimeters in length. The pregnant dog's nipples will enlarge
and darken, and it's abdomen will continue to swell. Owners should begin giving the dog cottage cheese or a hard boiled egg every
day, and increase the dog's overall food intake. The expectant canine should also being sleeping in its whelping (birthing) box.