Pregnancy is normally about 60-63 days long. Three to five kittens is the average litter size.
Determining if a queen is pregnant
For the first 2-3 weeks of pregnancy, you may not notice any changes. One of the first things noticeable is the lack of repeated heat cycles.
Several methods are available to determine pregnancy. Ultrasound may be used to check for fetuses as early as day 14 or 15. A pregnancy may be detected by your veterinarian around 17-18 days of age by abdominal palpation. Heartbeats are seen via ultrasound after day 24. Fetal skeletons may be recognized on radiographs after days 43-45. The later the x-rays are taken in the pregnancy, the more accurate they are. Around the fifth week of pregnancy, the abdominal enlargement begins and becomes more noticeable as the pregnancy progresses. Those queens with a small litter will take longer to 'show' than those with a larger litter.
Care of the pregnant cat
The pregnant cat should continue to have exercise to help maintain her muscle tone and keep from gaining too much weight. If a vitamin plus mineral supplement was not started before breeding, it should be started now. Do not oversupplement as that may be harmful to the developing kittens. If you are adding multiple supplements to the diet, get a list of all the ingredients and nutritional labels and take everything to your veterinarian to make sure it is still balanced. Poor diets may cause problems with the developing fetuses and with the queen.
The queen should have been on a premium adult food prior to pregnancy and for the first few weeks of pregnancy. Starting the fourth week of pregnancy, begin adding a premium kitten food to her diet. Each week increase the amount of the kitten food, so when she is in her final week of pregnancy, she is on all kitten food. Increase the frequency of the daily meals to three by mid-pregnancy or free feed her. She may need to eat small meals every 3-4 hours during the last week of the pregnancy as the kittens continue to take up more room. Remember that most fetal growth occurs in the last two weeks of gestation.
During the last week of pregnancy and the first 3-4 weeks of lactating, she may eat 1½-2 times the amount she ate before pregnancy. As long as she is gaining a healthy amount during pregnancy while not becoming obese and maintaining weight during lactation, she should receive the food.
If she has external parasites such as fleas or ear mites or internal parasites such as roundworms, discuss treatment options with your veterinarian. It would be preferable to treat her before she passes the parasites to the offspring.
With a few exceptions, (Drugs to Avoid in Pregnant and Nursing Cats) one should avoid using all medications in pregnant and lactating (nursing) cats. There may be instances in which a medication not recommended for use during pregnancy may need to be used to save the life of the queen, even though it may potentially harm the fetuses. Always consult with your veterinarian before administering any drug or supplement to a pregnant or nursing cat.
At least two weeks before the pregnant cat is due to have the kittens, a nesting box should be set up so she can become accustomed to it. A laundry basket with clean towels often works very well. If you wait too long, she may have the kittens in the closet, on your bed, or in the basement. Do not allow her outside as her due date arrives, or she may have the kittens outside.