What does ‘in heat’ mean for cats?
When a female cat is in heat, also known as “in season” or “estrus season,” it indicates that she is fertile and capable of becoming pregnant. The first heat cycle, also known as the heat season, typically starts when a cat is 4 to 12 months old. After being neutered, or spayed, cats no longer go into heat; an unspayed cat will still go into heat every year.
The cat heat cycle typically begins in the beginning of spring, in February or so, and ends in the fall, in October, unless the cat becomes pregnant or experiences a phantom pregnancy during this period. Unspayed female cats will typically stay fertile and come into season as they age, albeit less regularly.
What is a Cat Heat Cycle?
Cats go through physical cycles that get their bodies ready for reproduction, just like the majority of female mammals. In humans, this is called the menstrual cycle. It is known as the estrous cycle in cats and has multiple stages.
Female cats that are in the estrus stage are referred to as “in heat” and are hormonally responsive to sexual activity and procreation. Cats don’t usually bleed vaginally like humans do because they don’t shed uterine lining like humans do.
Because cats are seasonally polyestrous, heat cycles can recur every 14–21 days during a specific breeding season. Longer days—those with at least 12–14 hours of sunlight—mark the beginning of breeding season. This indicates that peak estrus occurs in the Northern Hemisphere between February and April and may last until October.
Heat cycles can begin as early as four months of age and last until the cat is spayed or has its ovaries bred. In cats, heat can recur every one to three weeks and last for an average of six to eight days. Thus, it is understandable why an unspayed female cat appears to be in heat nearly all the time.
Signs of Heat in Cats
A female cat in heat will exhibit a number of distinct behavioral and physical symptoms. Although it is uncommon to see bleeding during heat, a tiny amount of mucus-like discharge may occur. When a cat is in heat, they most likely display the following symptoms:
- Howling or crying out
- Showing more affection than usual
- Pacing or restlessness
- Licking genital area
- Decrease appetite
- Trying to escape (to find a mate)
- Spraying urine
- Assuming a mating position, called lordosis
These kinds of symptoms could indicate that your cat is in pain or uncomfortable. But the idea behind these actions is to draw the interest of an unneutered male cat so she can conceive. It could result in a false pregnancy if your cat mates but doesn’t become pregnant. She might display pregnancy symptoms for a short while before returning to estrus approximately six weeks later. Your cat will go through an infertile phase known as interestrus, which lasts for two to 19 days, if she does not mate with a male during estrus. After that, the cycle repeats.