By Dr Duncan Houston
A female cat that suddenly yowls, rolls and raises her hindquarters may be in heat. It can look dramatic, particularly during her first cycle.
Heat should not explain away every change. A cat that is painful, unwell or struggling to urinate needs a different response.
Quick Answer
Unspayed cats in heat commonly call loudly, rub, roll, become restless and hold the hindquarters up with the tail to one side. Heat can last several days and may recur during the breeding season if pregnancy does not occur. Keep her securely away from entire males and discuss spaying; bleeding, discharge, marked lethargy or urinary straining should not be treated as normal heat.
What happens during a heat cycle?
Heat, or oestrus, is the phase when a female cat is receptive to mating. Cats often cycle repeatedly when daylight conditions are favourable, and indoor lighting can affect seasonality. Puberty can occur while a cat still looks like a kitten, so waiting for obvious adulthood is not reliable pregnancy prevention.
Cats are usually induced ovulators, meaning mating can trigger release of eggs. A single escape may therefore matter. The Merck Veterinary Manual describes feline reproductive physiology and variable heat duration. A calendar is useful for recording patterns but cannot guarantee a safe mating-free interval.
Which behaviours fit heat?
- Persistent calling and increased rubbing or rolling.
- Raised hindquarters, treading with the back feet and moving the tail aside.
- Restlessness, attempts to escape and sometimes urine marking.
- Changes in attention-seeking, while remaining generally responsive and well.
Some cats show subtle signs. Appetite may change, but food refusal or a depressed, withdrawn cat deserves veterinary advice rather than an assumption that hormones explain everything.
Normal pattern or a medical concern?
| What you see | Recommended action |
|---|---|
| Calling and posturing in a bright, unspayed cat | Secure the home and arrange a reproductive-health discussion. |
| Heat-like behaviour after spaying | Book an examination; ovarian remnant tissue is one possible explanation. |
| Vaginal discharge, reduced appetite, vomiting or unusual thirst | Seek same-day veterinary care. |
| Collapse, severe pain or repeated attempts to urinate without urine | Go to an emergency clinic now. |
What else can look like heat?
Urinary tract disease can cause vocalising, genital licking and repeated litter visits. Pain, anxiety and attention-seeking can also change behaviour. In an unspayed cat, uterine infection is a serious possibility when she becomes unwell; discharge may be absent. A vet may examine her abdomen and urine and use blood tests or ultrasound according to the findings.
How to help your cat safely
- Keep her indoors with secure windows, screens and doors. Separate her from entire males, including related cats.
- Offer calm attention if she seeks it, brief play and a quiet retreat. Do not punish calling.
- Record the start of signs, appetite, litter output and any chance of mating.
- Contact your vet about spaying and tell them if she is currently in heat or may be pregnant.
- If she escapes or mates, ask promptly about the available options. Do not use home remedies or human hormonal medicines.
Common mistakes and prevention
Do not let a cat outside to “get it out of her system”, assume siblings will not mate, or try to trigger ovulation yourself. Calming products do not prevent pregnancy. Plan neutering with your vet before accidental breeding becomes possible; the appropriate timing depends on the cat and local practice.
Frequently Asked Questions
Do cats bleed when in heat?
Visible bleeding is not a typical heat sign. Ask your vet to assess its source.
Can a cat be spayed while in heat?
It may be possible, but the surgeon will assess the situation and discuss timing and surgical considerations.
Can an indoor cat go into heat?
Yes. Being indoors does not stop reproductive cycling.
Why is my spayed cat acting in heat?
Behaviour alone does not prove a heat cycle. A vet can investigate residual ovarian tissue and other explanations.
Recognising heat helps you respond calmly. Keeping her safe from mating and checking for illness are more useful than simply trying to stop the noise.
For more practical animal health information, explore ASK A VET™. Your own veterinary team can help tailor the next steps to your cat or dog.
The ASK A VET™ Tracker logs live location and activity trends, so a change in routine never goes unnoticed.
- Cats
- Heat Cycles
- Neutering
- Reproduction
Every ASK A VET article is written and reviewed by qualified veterinarians.
