Puppies should double their birthweight by 10 days of age. Kittens should be gaining weight by 10 days of age, too. If they are not receiving enough milk, they will cry constantly, be inactive, and fail to gain weight. They may not get enough milk for a variety of reasons. One reason could be that the mother disowns her babies or the litter is too large to be cared for properly. Another reason could be that the mother fails to lactate completely because of illness, mastitis, metrititis, or underdeveloped mammae. It could also be that the puppies or kittens are born prematurely or underdeleveloped and are so weak and sick that they cannot suckle. They may have a congenital defect that precludes adequate milk intake.
Commercial milk replacer for kittens and puppies is available to feed orphan kittens and puppies. You can also make the milk replacer at home:
3 ounces condensed milk
3 ounces water
4 ounces plain yogurt
3 large or 4 small egg yolks
Before feeding, warm the milk replacer to about 100 degrees F.
Increase the amount given as the puppy or kitten gains weight and responds favorably to the millk replacer.
Be sure to keep all feeding equipment clean.
Generally puppies and kittens will be fed 3 to 4 times a day.
Weaning puppies and kittens from milk to solid food should be done gradually. Encourage kittens to begin eating solid food at 4 weeks of age, and puppies at 3 weeks of age. At the beginning of weaning, offer a good quality food designed for puppies or kittens mixed with water or milk to make a thick gruel. Use a mixutre of 1 part dry food blended with 3 parts water. Most kittens will wean at 6 - 8 weeks of age while puppies will wean at 5 - 7 weeks of age. Early weaning and separation from littermates prior to 6 weeks can result in behavioral problems such as slowness to learn and more suspiciuos, cautious and agressive actions.
Avoid overfeeding puppies. They will eat 3 times a day until 6 months of age, then twice a day. Feed kittens all the food they will consume. They should be fed at least 3 times a day while they are growing.