Many times over, concerned owners are faced with the dilemma of whether their cat might be pregnant. It seems that one day the cat is svelte and in her prime, then the next, she looks like a little football on legs. There are certain signs which can determine the likelihood that the cat is carrying kittens, and once you know what to look for, they are almost unmistakable at confirming the pregnancy.
No matter how young your female, if she is in call, then she can be impregnated by an entire male. If you aren't sure whether your cat is calling or not, please read the associated article "Sexual Maturity in Cats".
Think carefully before allowing any cat to mate in this period, as carrying a litter can have life threatening implications, and can result in the death of your female and/or her young. Even experienced breeders lose cats and kittens to pregnancy related complications.
If a cat has been mated, then there is a high probability that she will be pregnant. The time and date of the matings should be noted where possible, but if your cat has simply been gone for a few days, note this time period, as mating will have occurred during the time she has been gone from home.
One may not realise initially that the cat has been successfully mated. A very early tell-tale sign is that all calling will stop and the cat's appetite will subsequently improve.
One of the earliest physical signs of pregnancy is what breeders term "pinking up". This normally occurs within 2-3 weeks of gestation, but is most evident at 21 days. The cat's nipples will enlarge and change to a nice rosy pink colour. This is very noticeable if it is being searched for, but it is worth noting that not all cats pink noticeably. Some only stay pink for a few days, while maidens, i.e. cats who have never carried kittens before, usually have a spectacular response, and the pink shows clearly. Some cats may show pinking much later in the pregnancy, so owners should be vigilant.
At four weeks' gestation, an experienced veterinarian should be able to feel the kittens in the uterus when the stomach is palpated. The kittens are 20-30MM long now, roughly the size of walnuts, and much easier to count at this stage. As the pregnancy progressed, they will become squashed together, and the vet will have trouble determining the litter size. Please do not attempt to palpate the cat yourself. Pressure applied too firmly or in the wrong place can damage the unborn kittens.
The fifth week sees the queen's appetite begin to markedly increase. She is now feeling the demands of her growing babies, and should be fed a high quality, complete cat food. Wet diets are best to keep her hydrated, particularly as kitten season normally coincides with the hotter months of the year. If you are feeding supermarket quality foods, then kitten food is preferable, as it has extra nutrition that she will need. If the food has a high meat content, then this is less of an issue. The queen may also experience morning sickness during the 3-5 week period, but this is perfectly normal.
At 7 weeks, there can be no doubt of pregnancy. The queen's abdomen is now distended and hard. A pregnant tummy should bulge out to the sides rather like saddlebags. If your cat is simply over-fed, her belly will hang straight down instead. Kitten movement can also be felt at this stage, but is likely to be quite faint initially, feeling not too dissimilar to gas bubbles. Her appetite will now be voracious to cope with the demands of the growing kittens, but this sometimes decreases in week 8 due to the over-crowding of her abdomen. If any cat shows these signs, then it is almost certain they are pregnant.
Cat gestation lasts approximately 65 days, but expect kittens anywhere from 63-70 days after the expected mating date.
Vets have a number of tests which can help determine pregnancy. Palpation, as already mentioned, can give an idea of litter size and expected length of gestation by feeling for the enlarged uterus and the small uterine swellings which indicate kittens, but unless the vet is very experienced in this area, it is often inaccurate. Some cats have been pronounced pregnant when they have in fact only been constipated. Other owners are assured the cat shows no evidence of pregnancy, only for their cat to deliver a litter a few weeks later.
Vets can also perform an ultrasound scan which mimics what a human mother has before her baby is born. This should definitely confirm pregnancy if it exists, but again, this is determined by the experience of the vet. Litter size and foetal ageing are difficult to determine with this test. The age of kittens is determined by measuring their crown-rump length. As they are dynamic and moving during the scan, this cannot be accurately measured. Kittens also curl around internal organs, hide behind one another and generally tried to avoid detection, so it is normal for the scan to predict a much smaller litter size than is actually present.
Later in the pregnancy, the vet can perform an x-ray. This allows accurate litter size predictions and foetal ageing, but it poses a risk to unborn babies. By the time calcification of the bones has occurred to make them visible on x-ray, the pregnancy is so far advanced that it is visibly obvious that the queen is carrying. X-rays are normally only used if a queen has had difficulties in the past, or if a breeder absolutely must know the exact litter size.
A hormone test can be run in early pregnancy to confirm whether a queen carries, but it needs some of the mother's blood to run, and very few laboratories are equipped to carry it out as the demand is so low.
For most owners, the physical changes exhibited by the queen, together with vet palpation, are enough to confirm a pregnancy. When all taken together, they are normally an accurate predictor of whether kittens are to be expected or not.