If you have an unspayed female cat, you’ll encounter her heat cycle sooner or later — usually sooner than expected. Understanding what’s happening physiologically and behaviourally makes the experience less alarming and helps you manage it more effectively.
When Does Mating Season Begin?
Domestic cats are seasonally polyoestrous, meaning they cycle through multiple heat periods during the breeding season. In South Africa, the primary season runs from around August through to March, following the longer daylight hours of spring and summer. Indoor cats exposed to artificial lighting may cycle year-round, as their bodies use light duration as the primary trigger.
Female cats can reach sexual maturity as early as 4–5 months of age, though 6 months is more typical. Small breeds and individual cats vary. There’s no reliable way to predict exactly when your specific cat will have her first cycle without simply observing her.
Understanding the Heat Cycle
Proestrus (1–2 days)
A brief introductory phase where the cat becomes slightly more affectionate and may attract male cats. Behavioural changes are subtle at this stage and easy to miss.
Oestrus (3–14 days)
This is the active heat phase, and it’s impossible to miss. The cat is receptive to mating and will display a range of behaviours designed to attract males. This is the phase most people refer to when they say a cat is “in heat.”
Interestrus (8–15 days)
If the cat doesn’t mate, she enters a brief resting phase before cycling again. This is one of the reasons a cat in heat seems to cycle relentlessly during the breeding season — she’s not in heat continuously, but the gaps between cycles can be short.
Anoestrus
The seasonal rest period, typically during the shorter days of autumn and winter in South Africa. Indoor cats with constant light exposure may not experience a true anoestrus period.
Signs Your Cat Is in Heat
The behavioural signs of oestrus in cats are distinctive:
- Loud, persistent vocalisation — a throaty, repetitive call that can sound distressed
- Rolling on the floor and rubbing against furniture or people
- Assuming the mating posture (lordosis) — crouching with hindquarters raised when stroked along the back
- Increased affection toward owners, followed by sudden irritability
- Attempting to escape outdoors
- Reduced appetite
- Excessive grooming of the genital area
Cats in heat do not bleed visibly the way dogs do. If you notice blood, that warrants a vet visit rather than an assumption of a normal cycle.
The vocalisation in particular can be alarming — some owners initially mistake it for pain. It isn’t, but it’s worth knowing that the calling can go on for hours, including through the night. If your cat’s nighttime restlessness is disrupting your sleep, this guide on training your cat to sleep at night may help for other periods, though managing a cat in active oestrus typically requires addressing the heat cycle itself.
Male Cat Behaviour During Mating Season
Intact male cats (toms) respond strongly to a female in heat. You may notice unneutered males gathering outside your home, spraying urine near entrances, vocalising loudly, and fighting with other males. This can create significant disruption in your neighbourhood.
Tom cats are capable of roaming considerable distances — several kilometres — to reach a female in heat. Their behaviour during this period can appear aggressive and unpredictable. Understanding this context is useful if your cat becomes aggressive during the season — in males, this is often hormonally driven rather than a trained behaviour.
Managing a Cat in Heat
If you don’t intend to breed, the options are:
Spaying
The permanent and most effective solution. Spaying eliminates heat cycles entirely and also reduces the risk of mammary tumours and pyometra (a serious uterine infection). In South Africa, most vets recommend spaying from around 5–6 months, before the first heat if possible. Some vets will spay during a heat cycle, though there’s slightly elevated risk due to increased blood flow to the reproductive organs.
Managing the environment
If spaying isn’t immediately possible, keep windows and doors securely closed. A cat in heat will look for any gap. Provide more indoor enrichment during this period — keeping her occupied doesn’t stop the hormonal cycle, but it reduces some of the restless behaviour. Maintain her routine as consistently as possible.
What doesn’t work
Giving a cat in heat extra attention typically amplifies the behaviour rather than soothing it. Punishment of any kind is counterproductive and will damage your relationship with her. The cycle runs its course — you can manage the environment but you can’t shortcut the biology.
Pregnancy: What Happens if Mating Occurs
Cats are induced ovulators — ovulation is triggered by mating, which means pregnancy rates after mating are very high. A cat can mate with multiple males during a single heat cycle, resulting in a litter with multiple fathers.
Gestation is approximately 63–65 days. Signs of pregnancy include a pinking and enlargement of the nipples from around 3 weeks, weight gain, and increased appetite. If you suspect your cat is pregnant, a vet can confirm via ultrasound from around 3 weeks.
South Africa has a significant stray and feral cat population. Responsible breeding and timely spaying make a meaningful difference to the welfare burden on shelters and rescue organisations.
