Teeth and Weight Can Help You Calculate the Age of a Kitten
The younger the cat, the easier it is for vets to determine about when they were born.
“Factors such as the cat’s size and teeth can be very useful in pinpointing an age,” says Dr. Stephen Horvath, clinical assistant professor at the College of Veterinary Medicine at Ohio State University.
Size of the Kitten
“Up until cats are about 4 to 6 months old, a good rule of thumb is that they gain a pound for every month,” Dr. Horvath explains. “So a 3-pound kitten is 3-months old, a 4-pound kitten is 4 months, and so on until about 6 months of age.”
However, Dr. Nappier says that this method isn’t foolproof. “If the cat is in poor health, weight is no longer a reliable age indicator.”
The other age indicator that can be used for kittens is their teeth.
A kitten’s deciduous (baby) teeth start to come in when they’re about 2 weeks old, and finish when they’re about 8 weeks old.
Then, at around 4 months old, the baby teeth start to fall out, and adult teeth start to erupt. A cat should have all of their adult teeth by the time they’re 7 months old.
“Once that happens, it’s really hard to tell how old a cat is by its teeth,” Dr. Horvath says.