My cat is having kittens

How did my cat get pregnant?

The fecundity (fertility) of the cat has been acknowledged throughout its history with man – it has in consequence been worshipped by some and persecuted as wanton by others. What it does mean, is that if you fail to neuter your female cat before she becomes sexually mature and you let her outside, an unneutered male cat is likely to find her and before you realise what has happened she will be pregnant! You are probably unlikely to notice this until she starts to get rather plump and wonder what you have to do. Here’s how it happens ...

What are the basics of cat reproduction?

Cats reach sexual maturity (and thus are able to breed) from around 4 months of age. Hence current advice to have your cat neutered around 4 months old to prevent unwanted pregnancies (see our information on neutering and timing of neutering).

The timing of reproductive activity is probably triggered by an increase in day length which signals that better weather is on the way bringing with it an availability of food animals for the cat so that when the kittens are born after a 9 week pregnancy the mother and kittens will have sufficient food. In the northern hemisphere therefore cat pregnancies and births increase in March, April and May and decrease from October to January, while in the southern hemisphere the reverse is found. Cats on the equator probably don’t have a great deal of change in their reproductivity throughout the year.

However, for female cats this time of ‘heat’ or coming into season, or oestrus, isn’t one long period but many short periods (each cycle is about 14 days long). During these periods the cat will exhibit what could be described as ‘flirtatious’ behaviour, rubbing and rolling on the floor, marking, and making a plaintive yet demanding rising and falling pitch known as ‘calling’. Owners who haven’t previously owned an unneutered female cat sometimes think that their pet is in pain and that these behaviours are signs of illness, whereas in fact they’re quite normal for a female cat in search of a mate.

Of course male cats (also known as toms) which have not been castrated are constantly on the search for females (also referred to as queens) which might be receptive to their charms! They will pick up the scent, sound and body language signals which the female is putting out and realise what is happening very much earlier than human owners. By the time we humans catch on, the cats will have mated if they have access to each other.

Several males may congregate around the female and, while a male on his own territory may be more confident of winning any fight that might break out and thus a chance to mate with the female, she may have her own preferences. She will not accept any advances from the male until she is ready. She then exhibits what is know as the lordosis position where she puts here rump in the air and front end on the ground and waves her tail to one side. The male grabs her by the loose skin at the back of her neck (the scruff ) and they mate briefly. At the end of this the female almost seems to attack the male cat. We do not really understand this but it may have something to do with the barbs on the penis of the male which face backwards – whether these cause pain as the male withdraws is not known, but the action probably has a very important effect.

Cats do not ovulate or release eggs into the fallopian tubes and into the horns of the uterus so that they can be fertilised until they have mated – unlike other animals which already have the egg in situ when mating occurs. So, in order to become fertilised, the egg must be released and the stimulus is mating; indeed it can take several matings to stimulate ovulation. The female may mate 10 to 20 times on the first day and may mate with several males over a period of four to six days. This long period of receptiveness gives the cat a chance to ovulate and to choose the best male; one which is healthy and in his prime.

Because it takes two days for the eggs to move down the fallopian tubes and reach the uterus and sperm survives for several days, the resultant litter may actually have several different fathers. The eggs implant in the uterus and the resulting fetuses line up in two rows in the two horns of the uterus.

If mating does not occur the eggs are not released and the cycle is repeated again about two weeks later.

How long does pregnancy last in the cat and what are the signs?

After the female cat becomes pregnant, her body slowly changes over the next 63 days as the fetuses grow. However, there’s very little outward change in the first weeks of the pregnancy, and the first sign owners may see is a ‘pinking’ (becoming more pink in colour) of the nipples, which also become more visible. She’ll then gradually put on weight, and as the day of birth approaches the milk glands begin to fill.

The female’s hormones also bring about changes in her behaviour and she’ll start to look for a good nest site in which to hide her kittens. Without the protection of a human home the safety of her kittens is far less certain. In the wild the site needs to be dry and well hidden, as it will be vital to the kittens’ survival. The female may even select several nests so that she has safe alternatives should any danger threaten her original site.

In a home environment owners may notice ‘nesting’ behaviour (probably in the final two weeks of pregnancy). The cat will look for a quiet, safe and often dark place to have her kittens. Owners may want to provide her with a cardboard box or bed with bedding if it becomes clear that this is the cat’s choice of site to have her kittens. The bed should be suitable for snuggling into but should not be able to wrap the kittens within pockets or folds. Cats choose to have kittens in all sorts of places – cupboards, under beds, in sheds etc – some even on their owner’s bed.

What happens during a normal cat birth?

Just before the birth the female cat may become restless or meow or purr or pant (or all or none of these things!) She will clean around the birth passage and the teats. It’s thought that she lays a trail of saliva for the kittens to follow to find a teat after they’re born. She will go through several different stages of labour (see our information on normal cat birth). Each kitten is born in a sac of amniotic fluid that the mother licks and nibbles to free the kitten. She bites through the umbilical cord and eats the kitten’s placenta, and using her rough tongue she cleans the kitten and stimulates it to breathe. Most cats (especially non-pedigree ones), will give birth without problem and will need no human intervention.

How do I care for newborn kittens?

The female encourages the kittens to suck and keeps them warm by lying on her side and encircling them. The kittens are guided by scent and warmth to her nipples where they find colostrum, the first type of milk to be produced which is rich in antibodies to help protect the kittens from disease in their early weeks of life.

The mother cat purrs while the kittens are sucking – the kittens are not able to hear when they are first born, but they can follow vibrations to move towards her. They have a built in rooting or nuzzling behaviour which helps them to find the nipple, latch on and stimulate the milk to flow. The sucking reflex then takes over and they feed. Kittens tend to return to the same nipple to feed, perhaps to stop them squabbling and to ensure that milk continues to be produced there because there is a demand.

At birth kittens weigh about 100g but this doubles in a week and triples in three weeks. Cat milk is high in protein and fat – necessary nutrition for this rapid growth. They initially feed for many hours a day and keep the milk flowing by kneading their mum’s stomach with their paws (the same behaviour they may show on our laps or on a fluffy blanket). The kittens remain highly dependent on their mother for two to three weeks for feeding, cleaning, defecation and keeping warm. By four weeks they are using litter and copying their mother’s use of the tray; at six weeks they are grooming themselves and each other and forming bonds with each other. By four weeks the mother starts to wean them off her milk and onto solid food and in the wild she would be teaching them about prey and hunting so they can be self-sufficient as soon as possible.

So if all goes to plan, then you don’t have to do much for the first few weeks except make sure that the mother cat is well fed and has the facilities she needs. As soon as you are aware of the pregnancy it would benefit the kittens and their mother to feed a growth type diet. This can continue to be fed after the birth of the kittens and until they are weaned. Occasionally mother cats become ill or cannot feed kittens for some reason and owners consider hand rearing. This is quite an undertaking if the kittens are tiny and the decision needs to be thought through carefully. Occasionally kittens seem to be rejected perhaps because they are ill or have a problem and trying to hand rear may prolong the suffering, so it is not always appropriate and needs time and expertise to do it properly. Kittens are very fragile, and raising them can be difficult, time consuming, and it is not always successful. See our information on hand rearing kittens.

How to tell the sex of a kitten?

It can be difficult to tell what sex a kitten is when it is small. As kittens grow this process gets easier. In female cats the anus and vulva openings are close together and look like the letter ‘i’. In a male cat there are small testicles under the anus and the penis is below these – see picture.

Sexing kittens is not always easy!


This is a female...


...and this is a male

How do I care for a litter of growing kittens?

Once you have a litter of kittens you have large responsibilities!! You are responsible for the mother and her welfare and for the kittens, both their physical health and in producing kittens which are prepared for life as pets in people’s homes. If you do not want any more kittens you will need to neuter the mother cat as soon as the kittens are weaned and she stops producing milk.

See our information below for more information on caring for a litter of kittens and producing happy healthy kittens confident to go to new homes and give their new owners years of pleasure.

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