Breeding a cat: the honest checks before you plan a litter

Quick answer

The decision is usually made in spring, under pressure from a queen who has been calling for three weeks. That is the worst moment to make it.

Cats are long day breeders. As daylight lengthens, queens begin cycling, and a queen who is not mated does not simply have one season and stop. She is an induced ovulator, so without mating she keeps returning to oestrus every few weeks and keeps calling.

That relentlessness is what pushes owners into breeding, and it is the wrong reason. This article is the set of questions to answer honestly before the decision, and the specific tests, risks and costs that separate a planned litter from a preventable disaster.

• A queen who has never ovulated will cycle repeatedly through the breeding season. That is normal physiology, not a sign she needs a litter.
• Blood typing both parents is a cheap test that prevents an entire litter dying in its first week.
• A genetic test that comes back clear does not mean a heart scan is unnecessary.
• Assume an emergency caesarean at three in the morning, and know in advance where you would go.
• If you cannot keep every kitten that does not sell, you are not ready.

Decide in 60 seconds

Why the season pushes people into it

A queen's reproductive cycle is driven by day length. As spring arrives, cycling begins, and in the northern half of the year a queen who lives outdoors will cycle repeatedly until autumn. A queen living indoors under household lighting may never get the seasonal break at all.

Within that season, the cat is an induced ovulator. She does not release eggs on a fixed schedule. Ovulation is triggered by the physical act of mating, and usually by more than one mating over a short period.

That single fact explains almost everything owners find distressing. If she is not mated, she does not ovulate; if she does not ovulate, she has no luteal phase; without a luteal phase she returns to oestrus within a couple of weeks and starts again.

The behaviour that follows is dramatic and frequently mistaken for illness or pain. A calling queen rolls, treads with her hind feet, raises her hindquarters, becomes intensely affectionate, may spray, and yowls loudly for days. She is not suffering in the sense owners assume, but she is under real physiological pressure, and so is the household.

Two things follow. First, the noise is not a reason to breed, because one litter does not resolve it; she will cycle again after weaning. Second, an unspayed queen who escapes even briefly during this period will very likely return pregnant, potentially with kittens from more than one tom.

The honesty test

Why do you want this litter?

The reasons that hold up are narrow: you are working within a breed programme, with registered cats, screened for the conditions that breed carries, and you can place or keep every kitten. The reasons that do not hold up include letting the children see it, recovering the cost of the cat, wanting one kitten from her, and thinking it will settle her down.

Could you afford the worst version?

The realistic worst case is an out of hours emergency caesarean, a queen needing intensive care afterwards, and a litter that has to be hand reared. Hand rearing means feeds around the clock, every few hours, for weeks, including toileting each kitten after every feed. That is a job, not a hobby.

Who is home?

Queening usually happens at night. Someone has to be present and awake enough to recognise trouble, and available to drive.

What happens to the kittens you cannot place?

Kitten season means shelters are at their fullest exactly when your litter is ready to leave. If the honest answer to "what if nobody takes the last two" is anything other than "they stay here", stop.

What happens to the queen afterwards?

Retiring and spaying her is part of the plan, not an afterthought. An unspayed queen carries a lifelong risk of pyometra, which is a surgical emergency, and a higher lifetime risk of mammary cancer.

Is she the right age?

A queen can conceive months before she is physically mature. Breeding a cat that is still growing is a welfare problem, and registries set minimum ages for a reason. At the other end, a first litter in an older queen carries more risk than a first litter in a young adult.

Is she the right weight and condition?

An obese queen has a higher rate of birth difficulty. A thin queen will lose more condition through lactation than she can afford. Condition should be assessed and corrected before mating, not during pregnancy.

The equipment is the least of it. What a litter actually costs is screening before mating, veterinary care during and after, and the time nobody budgets for.

The tests that are worth doing, and what they do not cover

Infectious disease, in both cats.

Feline leukaemia virus and feline immunodeficiency virus status must be known for the queen and the tom before they meet. Bringing an untested cat into your house, or sending your queen to one, is how these viruses enter a household. Vaccination status should be current before pregnancy, not during it, because some vaccines are not given to pregnant cats.

Blood typing, in both cats.

This is the cheapest test on the list and the one most often skipped. If the queen is blood type B and the tom is type A, kittens that inherit type A are born healthy and then absorb anti-A antibodies from her colostrum in their first day of life. Those antibodies destroy the kittens' own red cells.

The kittens fade, stop feeding, may pass dark red or brown urine, become jaundiced, and often die within days. Survivors sometimes lose the tip of the tail or the ears. It is called neonatal isoerythrolysis, it is entirely preventable, and it is more likely in breeds where type B is more common, including British Shorthairs, Devon and Cornish Rex, Turkish breeds and Birmans.

Prevention is simple: type both cats before mating. If the combination is risky, either choose a different tom, or plan with your vet to keep the kittens off the queen for the first day of life and feed a substitute, since the gut only absorbs those antibodies during a short window after birth.

Breed specific screening.

The specific tests depend entirely on the breed, and your breed registry or club will publish the current list. Established examples include polycystic kidney disease in Persians and related breeds, inherited forms of hypertrophic cardiomyopathy in Maine Coons and Ragdolls, pyruvate kinase deficiency and progressive retinal atrophy in several oriental and spotted breeds, and hip dysplasia in Maine Coons.

Why a clear DNA test is not the end of it.

This is the point most breeding advice gets wrong. A DNA test only tells you about the specific mutations it looks for. Hypertrophic cardiomyopathy in cats is not fully explained by the known mutations, so a genetically clear cat can still develop the disease and pass on the tendency. Screening by cardiac ultrasound, repeated at intervals through the cat's breeding life, is what actually detects it. Treat DNA results and imaging as two different tools that answer two different questions.

Condition, weight, dental health and parasite control all need to be right before mating rather than corrected during pregnancy.

Who has hard births, and why

Brachycephalic breeds.

Persians and Exotics combine a broad, round kitten head with a maternal pelvis that has not widened to match. Difficult births and caesareans are more common, and this is a known cost of the head type rather than bad luck.

Singleton litters.

A single large kitten is a classic cause of birth failure. Labour depends partly on signals from the kittens and on adequate uterine stimulation, and one oversized kitten in a roomy uterus often does not produce effective labour. If a scan shows one kitten, discuss a planned approach with the vet in advance.

A previously fractured pelvis.

This is the one that catches rescue owners out. Cats hit by cars frequently fracture the pelvis, and the fracture heals with a narrowed pelvic canal. The cat is entirely healthy and gives no sign of the problem until she cannot deliver a kitten through it. If your queen has any history of trauma, she needs radiographs before she is mated, not after.

Very young or overweight queens.

Both increase the chance of ineffective labour.

Previous dystocia.

A queen who needed intervention in a previous litter is more likely to need it again.

What labour actually looks like, and when to call

Gestation runs roughly 63 to 67 days. In the last week the queen will usually seek out somewhere enclosed, dark and quiet to nest. Give her that place well in advance, in a room the household is not walking through.

The first stage is restlessness, panting, purring, repeated visits to the nest and often loss of appetite. Contractions are not yet visible. This can last hours.

The second stage is visible straining, and this is where the clock matters. Agree exact thresholds with your vet in advance, and write them down. The commonly used ones are that strong, productive straining without a kitten appearing, or a long interval between kittens after active labour has begun, both warrant a phone call rather than more waiting.

Call immediately, at any point, for any of these: green or black discharge before the first kitten is born, a kitten visible at the vulva and not progressing, heavy fresh bleeding, a queen who becomes weak, collapses or has tremors, or a queen who stops labouring while you can still feel kittens.

After the birth, watch the queen as closely as the kittens. Fever, a foul smelling discharge, a hard hot painful mammary gland, refusal to eat, or a queen who ignores the litter all need same day attention. Tremors or seizures in a nursing queen are an emergency and can indicate a dangerous drop in blood calcium.

Queens choose enclosed, dark, quiet places to give birth. If you do not provide one she will find her own, usually in a wardrobe or under a bed at the worst moment.

The first weeks, and the things that go wrong quietly

Weigh every kitten on a gram scale every day. Steady daily gain is the single most reliable indicator that a litter is thriving, and it detects a failing kitten a day or more before it looks unwell.

A kitten that fails to gain, cries persistently, feels cool, or is limp needs help immediately. Neonatal kittens cannot regulate their own temperature well, cannot maintain blood sugar for long, and deteriorate over hours rather than days.

Keep the queen's environment warm, draught free and clean, and disturb the nest as little as possible in the first days. Handling is fine and necessary for weighing; a stream of visitors is not.

Plan the veterinary schedule before the kittens are born: worming, first vaccinations, microchipping and health checks all fall due before they go to new homes, and each has a timing that is set by the kitten's age.

Kittens should not leave for new homes until they are eating independently, socialised and old enough. Many countries set a legal minimum age, and reputable registries set a higher one.

If you have decided not to breed

Neutering is the answer to calling, and it is also the answer to spraying, to escape attempts, to fights with toms, to unplanned litters and to pyometra.

Timing is a conversation with your vet. The traditional advice to wait until after a first season is no longer standard practice in many countries, and there are good reasons to neuter before a queen can conceive, given how early that can be.

While you are waiting, keep a calling queen strictly indoors, secure windows and balconies, and remember that a determined tom will find a way in as readily as she will find a way out. Do not use hormonal suppression casually; it has side effects and should only be used on veterinary advice.

What never to do

Do not breed to recover the cost of the cat. It does not work, and the moment it starts to look profitable you have cut something that mattered.

Do not use an unregistered, untested tom because he is nearby and free.

Do not skip blood typing because the queen looks healthy. She will be healthy. The kittens are the ones who pay.

Do not accept a stud arrangement without seeing current test results and vaccination records.

Do not let a queen have back to back litters. She needs recovery time and the registries that set limits set them for good reasons.

Do not attempt to pull a kitten that is stuck. Traction applied by hand injures the kitten and the queen.

Do not give the queen any medication, supplement or wormer during pregnancy or lactation without veterinary direction. Several routine products are not safe at these stages.

Do not rehome kittens early, even to good homes. Removal before they are ready causes lasting behavioural problems.

What the vet will want

When to get help

Go now for green or black discharge before the first kitten, a kitten stuck part way, heavy bleeding, a queen who collapses, has tremors or seizures, or a queen who stops labouring with kittens still inside.

Same day for a kitten that is fading, cool, limp or passing dark urine in its first week, a queen who is dull, feverish, off food or has a foul discharge after birth, or a hard, hot, painful mammary gland.

Before anything else, book a pre breeding consultation. Almost every serious problem in this article is preventable at that appointment and unfixable afterwards.