A newborn puppy survives off its mother's milk until around 4 weeks of age when it can begin to transition over to solid food. A puppy can completely wean of its mother's milk by 7 to 8 weeks of age and eat a diet of dry kibble.
During the transition period from mother's milk to kibble, a small amount of warm water or the mother's milk can be added to the food to soften the kibble and make it easier for young puppies to swallow and digest. Gradually decreasing the liquid will help the puppy's digestive system adapt to the solid food. Puppies should eat a few times a day or as recommended by a veterinarian.