Raising newborn kittens is both challenging and time-consuming; it can be intensely rewarding and heartbreaking, as well. If you don't have the time or the emotional stamina to deal with the potential of losing kittens, you might leave the job to trained professionals. However, if your bleeding heart is ready to take on the challenge of stray babies, then go for it. Just make sure you can find a home for them all.
Birth Mother or Surrogate?
If the kittens are strays, yet being cared for by the mother cat, she will do the work of raising them and in most cases, will do a better job than humans who attempt to step in and bottle-feed. Bottle-feeding should be a last resort for kittens who are not otherwise nursing. It is a good idea to schedule a veterinary checkup to make sure everyone's healthy if the mama cat is docile enough to allow it. Some stray cats are not comfortable with human handling, and this can be especially stressful for new mothers. It is best to let the mama cat have space to feel safe to care for her new babies. Provide the mother cat with access to unlimited fresh water and food and give her a safe, quiet space where she can be alone with her kittens. Monitor the kittens to ensure they are all nursing, gaining weight, and staying warm. The rest is up to her.
If you encounter newborn kittens without a mother, or a mother who cannot nurse, you may need to act as the mother and provide the kittens' basic needs to ensure their survival. This requires round-the-clock care, at first, as if you just brought home a newborn baby.
First Trip to the Vet
Your veterinarian should examine orphaned newborns as soon as possible. Stray kittens can suffer from fleas and other parasites and may not have received the benefits of protective antibodies passed through their mother's milk. Orphaned kittens may need certain immunizations earlier than kittens who nurse until they are naturally weaned. And, any kitten showing signs of illness or distress including low body temperature, watery eyes, runny nose, diarrhea, lethargy, or failure to eat—should be seen immediately by a veterinarian.
Building a Nest
Next up on your surrogate to-do list is building a nesting box for your kittens. You can use an oversized cat bed with bumper sides or even just a cardboard box lined with clean towels. Either way, make sure your nest has tall enough sides so that the small babies won't tumble out. This also encourages the litter to stay together to generate warmth.
Since kittens that get cold can decline in health very quickly, make sure that the nest is located in a warm space in your home. For the first few weeks, you may have to provide supplemental heat in the form of a heating pad set on low. Wrap this pad in a thick towel and place it in the bottom of the nest. Make sure the nursery has an unheated section, as well. Instinctively, the kittens will move toward the cooler area if they become too hot.
Feeding Newborn Kittens
For the first few weeks, you will need to bottle feed the entire litter several times a day. Purchase formula made specifically for kittens, as well as kitten bottles and nipples. Follow the directions on the kitten formula for feeding by weight. Younger and smaller babies will need as many as twelve feedings around the clock (every two hours), so set your alarm for night feedings and recruit a family member to help. Bottle feedings can be performed in a comfortable chair with a kitten on your lap, wrapped in a warm towel. Situate him on his belly, and then present the nipple to encourage him to suck. Feed each kitten until they are no longer interested and have had enough.
At around three or four weeks old, the babies are ready to start eating soft food from a dish. Place canned kitten food and formula into your blender and process it until it's the consistency of a thick liquid. Prime each kitten by putting a bit of the mixture onto your fingertip, and then lead them to the dish. As the kittens start to enjoy their mush, gradually reduce the amount of formula in the mixture until they are eating soft, canned food as is. At this point, your kittens can also drink water from a bowl. But don't be surprised if there is a little water play before they decide to drink it.
Eventually, your kittens will graduate to all solid foods and this can include a combination of canned and dry kitten food. Since their tummies are small, offer them four or five small meals a day until they reach 8 weeks old.
Nurturing Newborn Kittens
The mother kitten performs various tasks that both ensure the health of her kittens, as well as promote bonding. If you're the head honcho, these tasks fall on you.
Mother cats encourage newborns to urinate and move their bowels by washing their bums with her tongue. You can encourage the same elimination pattern by holding each kitty (put a towel over your lap first) and gently stroking its hind end with a warm wet washcloth or moistened cotton ball. You should be rewarded with urine and/or a bowel movement after every meal.
Grooming and massaging your newborn kittens replicates the bonding activities the mother cat usually performs. A soft baby brush, towel, or soft bristled toothbrush can be used to stroke your kittens down their backs, on their tummies, and to clean any dirt from their bodies. Soft-touch and massage help kittens adapt more easily to your presence and their new home.
Litterbox Training
Kittens take to the litterbox as quickly as ducks to water. Use a low-sided box for training—the lid to a shoebox works perfectly. A non-clumping, pellet litter works best for untrained newbies, as the clumping-type causes digestive upset if they eat it. Once the kittens start eating on their own, place each one in the box within 5-10 minutes after eating. Scratch the litter with your finger to show them what it's all about. When they hop out, put them back in a few times, then leave them alone. If one has an accident on the floor, pick up a small amount of poop with a shovel and put it into the box so the scent may encourage them to use the litter box the next time.