Newborn kittens are very vulnerable to outside diseases, hypothermia and dehydration so you must give special care to their environment for the best chance of survival. If their mother is not present, you face even greater challenges.
Creating a Safe Space
Newborn kittens must be kept in a warm, safe environment free from other pets. They should be isolated in a safe, temperature-controlled room with only their mother. Before handling the kittens, be sure to wash your hands with a disinfectant since they are especially prone to diseases.
If you can't keep one room in the house warmer than others, use a heat lamp or a heating pad covered with a thick blanket to keep kittens warm. Put several blankets in the pen that they can use as nests. Also provide a cool space not covered by the lamp or heating pad so that kittens have a refuge from the heat if necessary.
Keep the area very clean. Rotate blankets twice a day and gently wipe the kittens down with a wet cloth each time you change the blankets to remove any urine or feces that may have gotten on them.
Once the kittens are around four weeks old, they will start to climb, play and explore. At this time, they will probably need more room, but the area will also need to be checked for harmful objects. Just as when baby-proofing, be sure to pick up all sharp objects and keep all cleaning products and human medications elsewhere. Animals often explore with their mouths, so anything that they shouldn't eat should be kept where they can't reach it. This is also the age when they begin to eat solid food and use the litter box.
Feeding Newborn Kittens
If you find kittens without their mother, you will have to bottle-feed them through the first weeks of their life. Kittens do not drink cow's milk. There are several formulas available in pet stores that are preferable. Feed the formula at room temperature, not hot or cold. Kittens need to be fed a precise amount around every two hours. Check with your veterinarian on how much to feed based on the size and age of your kittens.
Be sure the kitten is warm before you feed or his body will not process the formula. Warm him by holding him close to you first. Also, feed him while he is standing. Do not tip him like a baby or the formula may go directly into his lungs.
Kittens can dehydrate quickly so check frequently. Look in the kitten's mouth for lack of moisture or very pink tongue. Pull the skin on the back of his neck. If it doesn't rebound immediately, he may be dehydrated. If his urine is very yellow, not dilute, he is dehydrated.
If the mother is not present, young kittens also have to have their genitals stimulated to relieve themselves. This can be done with a warm, wet washcloth to imitate the mother's lick. This needs to be done every two hours until they are about three weeks old.
Raising kittens can be difficult but rewarding. If you give them a clean, warm, safe environment, they will be able to grow into healthy cats.