However, there are times when the mother dog cannot feed her pups, leading to an unhealthy and malnourished generation. Therefore, a puppy milk substitute may be necessary for the puppy in this case. Replace the mother's milk your puppy is missing out on with a special powder or milk made just for puppies. Puppies are carefully monitored to ensure that they are receiving an appropriate diet that will allow them to reach their full genetic potential. Once they grow old enough, they can start eating solid food and treats. You can find some good supplements at Whimzees, a brand that values dog's needs and has everything made with natural ingredients.