Pet Nutrition Stages
ASPCA Pet Nutrition and Science Advisory Service

Growing Animals - Puppies & Kittens
Newborn kittens and puppies receive total nutrition
from mother's milk for about the first four weeks of
life. After that, food is gradually added, and after a
few more weeks they are fully weaned. During the
first weeks of life, body weight may double or triple
and this rapid growth will continue (although at a
gradually decreasing rate) until maturity. Large
amounts of energy and nutrients are required in
balanced quantities to support this spectacular growth

Kittens: Kittens are best fed mom's milk; it's perfect for their needs. However, circumstances
may require that the kittens be fed a "milk replacer." If the queen is ill, has an extremely large
litter, doesn't produce enough milk or wanders off or dies, it is necessary to feed the kittens a
commercial milk replacer. A properly formulated milk replacer can come very close to matching the
growth of kittens nursed by the queen.  

Generally, orphaned or hand-fed kittens will be offered moistened kitten food at about three
weeks of age. The "moisture" should be a commercial milk replacer and be gradually reduced over
time until the kittens are eating dry kitten food at about five or six weeks of age.

Initially, the food will be more of a play thing than food, but the youngsters will soon catch on as
they watch mom eat her food. By the time the kittens are five to six weeks old, they should be
nibbling on their dry food consistently. This process of gradually introducing their kitten food is
important in training the kittens to eat when they are weaned. It also helps the queen by
providing a separate source of nutrition for the rapidly growing kittens.

After weaning, kittens are usually fed free choice - dry or nutrient-dense canned food - with fresh
water available at all times.

Most queens will suckle their kittens until 7-8 weeks of age. By this time, 80 - 90% of the kitten's
total nutrient intake should be from kitten food. Kittens need large amounts of energy equaling
about two to three times that of an adult cat on a kilogram of body weight basis. Kittens also
need about 30% of total energy from protein. Therefore, kitten food must meet all the nutritional
needs, including high amounts of energy and protein, from weaning until maturity at about one

Puppies: As with kittens, puppies occasionally need a replacement for the bitch's milk. Milk
replacer for puppies is used similarly to milk replacer for kittens as described above but should have
pup-specific instructions on the container.

Puppies generally begin eating puppy food three or four weeks after birth (whelping) and are
completely weaned by seven or eight weeks. They require up to twice the energy intake of
adults per kilogram of body weight and need to have 25% to 30% of total energy provided by
protein depending upon their breed.

Prior to weaning, as with kittens, puppies should have puppy food available. These meals should
begin when the pups are three to four weeks old and be small quantities at first. Puppies often
play in their food when it is first introduced, but they will quickly learn its value. By the time the
pups are ready to wean at six to eight weeks old, they should be eating their dry food
consistently. This is important training for the pups. It also helps the bitch by providing a separate
source of nutrition for the rapidly growing puppies.

Small breeds of dogs reach mature body weight in nine to twelve months, while giant breeds may
not be mature until 24 months of age.

Small breed puppies are those whose adult size will be 20 pounds or less. These pups can often be
fed free choice from weaning. With the constant availability of food, most will develop good eating
habits and not become overweight. Owners with other pets or concerns about overeating should
feed their puppies by the portion control method.

Most medium breed puppies (adult size between 20 and 50 pounds) and all large or giant breed
pups (adult size over 50 pounds) are best fed with the portion control method.

The Challenge of Feeding Puppies: If puppies are allowed to over-eat, they may consume too
many calories and too much calcium, grow too rapidly and develop bone growth problems. In
breeds that are prone to these diseases, such as many large and giant breeds, overfeeding can
lead to an increased frequency of hypertrophic osteodystrophy (HOD), osteochondrosis (OCD) and
hip dysplasia. The formation of the young growing bone is disrupted and the resulting
malformation, lameness and pain may cause serious clinical disease.

The clinical signs seen with these bone growth diseases include bowing of the front legs.
Sometimes, these signs are misdiagnosed as weak bones due to calcium deficiency (rickets).
Rickets is a very uncommon disease so it is important to accurately diagnose these bone diseases
by x-rays. Adding more calcium to the diets of dogs with HOD, OCD or hip dysplasia will actually
worsen the diseases and may result in life-long damage to the bones.

Therefore, with large and giant breed puppies, it is important to aim for a slower rate of growth.
Do not over-feed or try to push the growth rate too fast. Controlled feeding of a balanced diet
specifically made for large and giant breed puppies facilitates optimal skeletal development.
Remember, the adult size of a dog is determined genetically, not by how fast it grows.

             © 2004 ASPCA
Pet Nutrition
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