A female, once sexually mature, will go into heat (also known as estrus). Cats are seasonally polyestrous which means they will go into heat multiple times a season until they mate. Season usually starts a few months after winter solstice and usually ends in September or October. Indoor cats who are only exposed to artificial lighting may stay in season year round! Estrus itself will last 4 – 10 days and will cycle (about every 2 to 3 weeks) until the female mates, is spayed, or goes out of season. During this time the female will become fairly agitated: thrashing about, rubbing on floors and furniture, spraying, rolling about restlessly, lifting her tail to attract a mate, and crying or meowing loudly. Males in response to a female’s heat will also have similarly extreme personality changes. In search of this willing mate he will do whatever he can to wander outside, he will also spray incessantly, mark his territory, and meow loudly. Many males also get fairly aggressive during this period.
As a general rule, unless you are a breeder, it is best to always spay or neuter your pet for many medical and behavioral reasons. One female cat and her offspring can produce over 400,000 cats in just seven years. Spaying/neutering your pet will ensure that your pet will not contribute to the pet overpopulation problem.
A female cat is spayed, this means that her ovaries and uterus (reproductive organs) will be removed. Usually she can be spayed after 6 months of age or in between heats or litters.** Your cat can be spayed during heat but it is more complicated and there is a slight risk due to increased vessel size and lowered clotting ability. If your female is not spayed she we often be in heat. This means meowing, crying, spraying, pacing and roaming the house (or outside if there is anyway to get out – beware a cat in heat is very, very clever) to look for a male. Unspayed females can also suffer uterine infections or breast cancer.
A male cat is neutered – this is the surgical removal of the testicles. This is a very simple procedure (much simpler than being spayed) that can be done after 6 months of age.** An unneutered male will go through severe spraying, howling, marking of territory and looking for a mate. An indoor male will do just about anything to get outside and find a female. Unneutered males are also prone to severe aggressiveness and territorialism.
** There is much debate going on about the *best* time to spay/neuter. Cats can be spayed/neutered earlier than 6 months of age, studies are still in progress on whether or not such early spaying/neutering is more or less beneficial than waiting till the cat is older than 6 months of age. If you are in doubt about when to spay/neuter consult your vet.