Cat Pregnancy Stages

Mother cat and kitten
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Responsible pet ownership involves spaying and neutering cats. Not only does spaying reduce the number of unwanted cats, but it also protects your own cat from contracting various diseases, like cancer, that can occur in the reproductive system. However, if you're the owner of a purebred cat whose kittens are in high demand, or you've taken on a pregnant stray, understanding the stages of pregnancy will ensure a healthy gestation period.

Fertilization

In order for a cat to conceive, she must first be fertile, or "in heat." An unspayed cat's fertility stage occurs every two to three weeks during spring and summer, as the sunlight triggers the release of hormones that activate ovulation. When your cat is in estrus, she is ready to mate and her eggs will accept fertilization for approximately seven days. During this time she will generally be much more vocal and affectionate.

The fertilization of a cat's egg (ovum) involves several steps. Each step results in a new stage in the embryo's development and implantation in the lining of the uterus. This process occurs roughly two weeks after fertilization.

Embryo Development

By the third week of gestation, as the embryos start to develop, your cat will gain weight and increase her intake of food. This marks the beginning of organ development in the embryos and creates a surge of hormones in your cat. At this time, your cat's nipples may become swollen and darker in color. 

As the embryos continue to develop, the highly-evolved cells of the head (cranium) and body (thoracic region) develop first. The placenta begins to form at the time of implantation and allows for the exchange of nutrients and waste products between the mother and embryo.

Fetus Development

At approximately 4 weeks, when most of the organic structures have been formed, the embryos become fetuses and the first trimester is completed. From now until birth, the growth of the fetuses will be your cat's main objective, requiring a great deal of her body's energy. Make sure to provide as much high-quality food as she'll eat during this stage. You should feed a food that is AAFCO approved for growth and development. This is also the time when a veterinarian or trained professional will be able to feel the baby kittens inside her abdomen; however, this window is fairly small as the production of amniotic fluid as the fetus develop can make them hard to feel.

Pre-Labor

As your queen nears her due date (approximately nine weeks from fertilization), she will exhibit clues to the arrival of kittens. This includes nesting—snooping around in closets and secluded areas for an appropriate place to bear her kittens. The time is ripe for you to prepare an area in a private place, with a box or basket lined with soft towels. While she may decide, instead, to give birth on the cold, hard floor of your bathroom, at least you tried to accommodate her needs.

Increased affection is another sign of impending labor. Your cat may want to be around you all the time. But it could go the other way, as well (hormones are known to do crazy things). A previously affectionate cat may become withdrawn and seek solitude. Either personality change is completely normal.

About twenty-four hours before birth, your cat may have milky discharge coming from her nipples. This indicates "go time"—kittens are on their way.

Cat Care

If you are fostering a pregnant cat or have welcomed a stray into your home, take her to the vet for a "well-check" immediately. Make sure they test her for FeLV (feline leukemia virus) and FIV (feline immunodeficiency virus) and discuss the pros and cons of vaccinating during pregnancy.

Assuming your cat is healthy, proper care during pregnancy includes a diet high in nutrients, along with fresh, clean water. She should also be kept indoors at all times. During pregnancy, switch your pregnant cat to premium-quality kitten food and continue feeding her this way until after the kittens are weaned. 

Potential Problems

Problems with pregnancy or parturition are rare, but can be serious if they occur. For this reason, it is important to have at hand the phone number and location of the closest emergency veterinary clinic—everyone who has lived with cats for any length of time knows that they never get sick during normal clinic hours.

In general, any unusual symptoms during gestation should be followed through with a call or visit to your veterinarian. This is an important part of the care of a pregnant cat.​ Although many pregnant cats go through gestation trouble-free, there are potential problems that can occur. Learn to spot the specific symptoms of trouble and what action to take to ensure the health of a pregnant cat and her fetuses. The following are a few conditions to be aware of so that you can spot the symptoms if they should occur, and take proper action.

Eclampsia

The depletion of calcium in the bloodstream can result in eclampsia, a life-threatening disease, which sometimes can occur during the last stages of pregnancy or right after parturition due to the consumption of high levels of calcium to make milk. A calcium supplement can help prevent this potential problem, particularly when caring for a pregnant stray cat, whose previous diet was undoubtedly minimal.

Signs of Eclampsia in Pregnant Cats

  • Behavioral Symptoms: Restlessness, pacing, panting, and irritability.
  • Physical Symptoms: Drooling, stiffness in gait, loss of coordination, and pain when walking, muscle spasms and seizure-like activity.

Eclampsia is a veterinary emergency, and the cat should be seen immediately by a veterinarian at the first signs of symptoms.

Spontaneous Abortion

Poor health of the pregnant cat or certain infections may result in malformed fetuses, which will be aborted spontaneously. Usually, the fetuses are simply resorbed by the mother's body and no symptoms occur. Or the fetus may be stillborn with no prior symptoms or signs. If symptoms do occur, they may include fever, bleeding from the vagina, inappetence, and depression.

All symptoms of abortion should be considered a veterinary emergency, and the pregnant cat should be seen immediately. She will need to be examined in case she retains any remaining fetuses, alive or dead.

Resorption

Resorption is an interesting phenomenon in which a dead fetus is completely absorbed by the queen's system. There are rarely any outward symptoms when resorption occurs. Since there are usually multiple kittens in a litter, you may never know this occurred as the birth of the rest of the kittens will proceed as normal. If fewer kittens than expected were born, a veterinary visit is essential to ensure that there are no remaining fetuses inside the queen.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.