Female cats may enter heat several times during a breeding season. When a female cat is in heat, she is fertile and will make every effort to find a male cat in order to reproduce. A heat period lasts for between 5 and 14 days, and during that time, even if she is less than a year old, she is capable of becoming pregnant. Preventing cat pregnancy takes effort on the part of the cat's owner.
Spay the cat. Spaying is a simple surgical procedure performed by a veterinarian. It renders the cat surgically incapable of reproduction and also prevents her from going into heat.
Recognize when the cat is going into heat. Cats who are going into heat start to meow loudly, become restless and irritable, and roll on the ground, demanding petting. She may also urinate more frequently or assume a mating position, with her hindquarters high in the air.
Keep the cat indoors when you notice her going into heat. Not only will she seek out male cats, but she can also draw male cats to her with her meowing and her scent. Keeping her indoors prevents her from making contact with outdoor males.
Keep the cat in a blocked-off portion of the house if there is an intact male cat in the household. This can be difficult if there is a lot of traffic between the two areas of the house, but it is important to keep the unaltered cats apart if you do not want kittens.