When a cat is ready to have her kittens, she usually licks her vagina and abdomen incessantly, as explained by veterinarian Dr. Ron Hines. She also loses her appetite, grows restless, becomes anxious and wanders around the house looking for a comfortable place in which to give birth to her kittens and take care of her litter.
According to Dr. Hines, a cat that is ready to deliver her kittens also releases a vaginal discharge. However, she generally licks it away before it can be detected by her owner. Immediately before she delivers her kittens, a pregnant cat also generally paces the room, yelps loudly and sits with her mouth open. Perceptive owners notice that the pregnant cat's breathing escalates and that she lays down on her side in an attempt to press downward and release the kittens.
If an owner suspects that a cat is about to go into labor, Dr. Hines advises confirming this by inserting an over-the-counter personal lubricant or margarine into the rectum of the cat before using a thermometer to measure the cat's rectal temperature. After three minutes, a temperature reading that is below 100 degrees Fahrenheit or 37.8 degrees Celsius is an indicator that the cat's expected time of delivery is within 24 hours.