Now, what about the babies? Well, it may sound obvious but the ideal food for them is their mom's milk. Therefore, it should be avoided to bottle feed puppies and kittens unless it is really necessary, due to sickness of the mom or excessive number of animals in the litter. At three weeks of age semisolid food can be introduced to puppies and kittens. This can be made of smashed dry puppy food mixed with water, not with milk. At five or six weeks of age the litter can be weaned from a nutritional point of view, even though the separation from the mom and littermates should be done later for behavioral reasons.