10 Interesting Facts About Newborn Kittens

By Aly Semigran

From the moment they are born, kittens have a unique set of needs to grow and thrive into healthy, socialized cats. Here are 10 interesting, must-know facts about newborn kittens from our vet experts.

Kittens gain weight at a rate of about 4 ounces per week, which means they should weigh around 1 pound by the time they reach 4 weeks of age, says Dr. Aimee Simpson, the medical director of the VCA Cat Hospital of Philadelphia. “Kittens should continue to gain about a pound a month until the age of 6 months,” she says. 

Kittens require a heat source for the first two to four weeks, such as a heating pad for pets, Simpson says. The ideal ambient temperature for newborn kittens is 90 degrees Fahrenheit with 55 to 65 percent humidity, she says. “It's important to provide them with room to crawl away from the heat source to prevent overheating and thermal burns.”

Kittens are born with their eyes and ear canals closed, Simpson describes. Their eyes will open in about seven to 14 days, and their ear canals will open between 10 and 14 days old. All kittens are born with blue eyes, she adds. Their true iris color will be evident by 8 weeks of age. 

If you are bottle-feeding kittens, they should be placed with their stomachs down—not on their backs—to simulate a natural nursing position and decrease risk of aspiration, Simpson says. Kittens start to eat solid food at 3 to 4 weeks old. 

Kittens who are not getting enough food could have low blood sugar, which can be life threatening, warns Dr. Renee Rucinsky, a board certified feline specialist at the Mid Atlantic Cat Hospital in Queenstown, Maryland. Hypoglycemia is a major concern with kittens, particularly it they have been orphaned, she says.

Kittens must be stimulated to go to the bathroom, Simpson says. In nature, this is done by the queen cat licking her kitten’s rear end. If the queen is not present, you can gently stimulate this area with a warm, moist cotton ball.  

According to Simpson, kittens will begin to erupt their deciduous (baby) teeth at 3 weeks of age. At 14 weeks old, they will begin to lose their deciduous teeth, beginning with their central incisors. By about 6 months of age, kittens will have all their adult teeth.  

Kittens should be able to stand by 10 days of age and walk by 21 days, Simpson says. Around 4 weeks old, they begin to display the fun, crazy kitten behavior we know and love so well, Rucinsky adds. Kittens typically learn appropriate behavior between 4 and 7 weeks of age. “For instance, if a kitten is playing too rough with their siblings, they are going to get that instant feedback,” Rucinsky says.  

Fleas can cause life-threatening anemia in young kittens, Simpson warns. “Since most flea medications are not safe for cats less than 8 weeks old, we recommend bathing kittens with fleas using a gentle dishwashing soap.”

Mom cats do a good job of weaning their kittens off them. As Rucinsky puts it, “They’ll politely suggest that the kittens move on.” However, it’s important that during the pivotal first eight weeks of a kitten’s life, she stays with her mom and her siblings to hone in on her socializing. “If you take a kitten away too early, they miss out on a lot of important social skills,” Rucinsky stresses.