Coping with a cat in heat is an experience most cat owners would sooner do without. If you plan on having your cat spayed and are just waiting until she's old enough, you may want to adjust that timetable. Your sweet, leggy kitten could be in hormonal turmoil well before she hits the 6-month mark. Here's how you'll know when she's in heat.
Feline Puberty Arrives
The age a cat reaches puberty will vary from kitten to kitten, just as with humans; and much depends on factors such as environment and breed. Outdoor or feral kittens may reach maturity earlier, especially if intact male cats are around. Siamese cats can show signs of puberty as soon as 4 months of age, while other breeds may not reach sexual maturity until they're 10 months old. In general, by 5 to 6 months of age, cats have reached adolescence. Female kittens can then go into heat and become pregnant even though they're little more than kittens themselves. Cats being bred intentionally shouldn't be permitted to get pregnant until they're at least a year old, so they can develop the instincts and emotions to cope with motherhood.
What's Happening in Her Body
When a cat goes into heat, her body is fertile and receptive to mating. The pineal gland in her brain responds to changes in day length and secretes the hormone melatonin. Melatonin plays a key role in the cat's reproductive cycle, because when daylight increases, the production of melatonin decreases. This decrease affects the area of a cat's brain called the hypothalamus, where reproductive hormones are formed. These hormones move from the pituitary gland to the cat's ovaries and uterus, where they exert their effects. As the cat enters puberty, there's an increase in the reproductive hormone estrogen, which causes the cat to go into heat. You may even see a slight mucous discharge, sometimes with a small amount of blood.
Unmistakable Signs of Heat
A cat in heat emits long howling meows. She's putting the word out to males that she is ready and available. Her love songs will continue until she mates, or the heat cycle ends. She'll display affection, rubbing her head and rear end against you, other cats or the furniture. She will mimic the mating posture, with rear end and tail raised. And she may spray, her tail quivering slightly as she leaves her estrogen-heavy urine on walls. An indoor cat will do her best to escape to the outdoors, and male cats in range will howl, spray and behave aggressively.
How Often She'll Go into Heat
Cats can breed nearly year-round, from late winter into early autumn, with the heaviest "kitten season" running from March through September. Especially during the increased daylight hours associated with spring and summer, a cat will go into heat every 14 to 21 days for about seven to 10 days. She will display frustration and irritability until she mates or is spayed -- or until the darker days of autumn. A cat that has given birth can go into heat as soon as seven to 10 days after delivery, but usually takes about four weeks.
Getting your cat spayed prevents her discomfort -- and yours, as you watch and hear her behavior, and avoids the risk of mammary cancer and uterine disease. It also avoids adding to the cat overpopulation problem. If your cat happens to be in heat, it's best to wait until it passes to have a vet spay her.
If She's Been Spayed...
When a cat is spayed, her uterus and ovaries are removed. In rare instances, a small amount of ovarian tissue may remain in the cat's body and respond to chemical signals from the brain to make the hormone that results in estrus, or heat. If this happens, the cat cannot become pregnant -- her uterus is gone -- but she may show signs of heat. The lining of the cat's remaining vagina may also bleed in response to hormones, simulating signs of heat. Finally, a recently spayed cat may also exhibit heat symptoms while her hormones settle down.