Cat in Heat: Signs, How Long It Lasts, Cycle Timing & Spay Benefits

What does “in heat” mean for cats?

Heat (estrus) is when an intact female cat — a queen — is fertile and receptive to mating. Unlike dogs, cats do not usually have a long bloody discharge phase that owners notice. Instead, heat is dominated by behavioural and vocal changes that can be intense and exhausting for households.

Cats are seasonally polyestrous in many climates: cycles cluster when daylight is longer (spring through autumn in temperate regions). Indoor cats under artificial light may cycle year-round. Spayed cats do not go into heat because the ovaries (the source of the hormonal drive) are removed.

Induced ovulation: how cats differ from dogs

Dogs typically ovulate spontaneously during their cycle. Cats usually ovulate in response to mating (induced ovulation). Multiple matings increase the chance of ovulation and pregnancy. That biology explains why:

• An unspayed queen can become pregnant very efficiently if she escapes outdoors even briefly
• Heat may end after successful mating and ovulation, then progress toward pregnancy or a non-pregnant luteal phase
• Without mating, many queens simply return to heat again after a short interval

This is also why “just one night outside” is a common path to an unplanned litter.

Signs a cat is in heat

Classic signs include:

• Loud, persistent calling or yowling — often worse at night
• Restlessness, pacing, and reduced appetite in some cats
• Increased affection or, conversely, irritability
• Rolling on the floor, rubbing on furniture, and scent marking
• Lordosis — crouching with front end down, hindquarters raised, tail to the side
• Treading with the back legs
• More frequent urination or spraying-like behaviour in some queens
• Attraction of neighbourhood tomcats to doors and windows

Bloody discharge is uncommon compared with dogs. If you see significant vaginal bleeding, foul discharge, lethargy, or pain, contact your vet — that is not typical heat.

How long does a cat stay in heat?

Individual queens vary. Some have short, subtle heats; others vocalise dramatically for a week. Siamese and related breeds are often especially vocal.

How often do cats go into heat?

During the breeding season, an unmated queen may cycle every few weeks. That means months of repeated heat behaviour if she is not spayed and not bred — a major welfare and lifestyle reason many owners choose early sterilisation.

Age of first heat is often 4–6 months, but can be earlier in some individuals or later in others. Do not assume a young kitten is “too young” to conceive.

Caring for a cat in heat

If your cat is intact and currently in heat:

1. Keep her strictly indoors — secure windows and balconies; tomcats are persistent.
2. Provide extra enrichment and comfort — quiet rooms, familiar bedding, interactive play when she wants it.
3. Use washable covers on favourite resting spots if she is restless or marking.
4. Do not give human sedatives or hormonal remedies from the internet — many are dangerous.
5. Discuss spay timing with your vet; many clinics spay cats in or around heat, though surgery can be slightly more vascular — your vet will advise.

There is no reliable “home remedy” that safely stops heat. Temporary hormonal drugs exist in some regions but carry risks and are not a substitute for spaying in pet cats.

Spay benefits beyond stopping heat

Spaying (ovariohysterectomy or ovariectomy) ends heat cycles and prevents pregnancy. It also:

• Eliminates the risk of pyometra (life-threatening uterine infection)
• Greatly reduces mammary cancer risk when performed before repeated heat cycles
• Prevents unplanned litters that contribute to shelter overcrowding
• Removes the stress of repeated calling, escaping, and neighbourhood tomcat pressure

Recovery is usually straightforward in healthy cats. See your clinic’s guidance on rest, cone use, and incision checks. For post-op expectations, read our cat spay recovery guide when available, and pair heat education with cat pregnancy if breeding or accidental mating is a concern.

Heat vs illness: when to call the vet

Heat is uncomfortable for owners but not an emergency by itself. Call your vet if:

• Vocalising comes with lethargy, hiding, fever, vomiting, or appetite loss
• There is bloody, pus-like, or foul vaginal discharge
• She strains to urinate or cannot pass urine (urinary obstruction is more common in males but any cat in distress needs urgent care)
• Heat-like behaviour appears in a previously spayed cat (rare ovarian remnant syndrome is possible)
• You want to time spay surgery or rule out pregnancy after a known mating

Breeding considerations (brief)

Responsible breeding requires health testing, planned pairings, kitten socialisation capacity, and lifelong homes — not simply allowing a heat to “run its course” outdoors. Most pet cats are happier and healthier spayed. If you are considering breeding, work with a veterinarian experienced in feline reproduction before the first heat.

Related guides: Cat pregnancy · Cat spay recovery · Dog in heat · Cat not eating