Norwegian Forest Cat

　　When we decide to raise a kitten, many professional sources recommend female cats to cat owners because of their delicate temperament and loyalty to their owners, and this is indeed true. However, when their first heat rushes in, they will focus on loudly howling and continue throughout the night. Heat causes their fur to dull, appetite to decline, and weight to drop rapidly.

　　Owners are often surprised by their precociousness, like tropical fruits, but don’t know how to handle it. As a result, many human methods are applied to cats: for example, feeding contraceptives to cats. Feeding human contraceptives to female cats to prevent heat or ovulation does have some effect, but an increasing number of cases show that long-term use of this method to control heat and reproduction in female cats is very wrong and causes great harm to the cat’s health.

　　I. What ingredients are human contraceptives composed of?

　　The main components of human contraceptives are estrogen and progestin, which inhibit ovulation. Because various contraceptives differ in ingredients, doses, and formulations, the key mechanisms of contraception differ. Even human users should take them under a doctor's guidance.

　　II. How does the reproductive system of cats work?

　　A sexually mature female cat’s estrus lasts 5 to 8 days, up to a maximum of 20 days. During this time, female cats release large amounts of sexual hormones and use unique and loud calls to attract male cats.

　　Many authoritative materials prove that a female cat’s estrous cycle is indirectly regulated by day length; changes in daylight rhythm stimulate the hypothalamus to release corresponding hormones. As the day lengthens, the brain sends signals telling the body that it is breeding season. Indoor house cats, affected by fluorescent lights and other artificial lighting, can come into heat during any season of the year.

　　Cats are induced ovulators, meaning ovulation must be induced by mating activity. Ovulation usually occurs about 24 hours after mating. If there is no mating or fertilization failure during the heat period, the female cat may come into heat again.