Estrus ("heat") is the mating period of female animals. When estrus occurs, animals are said to be "in heat" or "in season." Cats normally have their first estrous cycle between 5 and 10 months of age, with the average age around 6 months.

The female cat has 2-4 estrous periods every year, each lasting 15-22 days. If she is bred, estrus seldom lasts more than 4 days.

If successful mating does not occur, estrus may last for 7-10 days and recur at 15- to 21-day intervals. It is possible for an unmated female to cycle every 3-4 weeks indefinitely.

Cats also have an estrous period 1-6 weeks after giving birth, so a female may be nursing one litter while pregnant with another.

Behavior

Since there is usually no obvious vaginal discharge or swelling of the genitals during estrus in cats, as is seen in dogs, behavioral changes are the only obvious signs that your cat is in estrus.

A cat in estrus carries her tail to one side, keeps her hindquarters elevated, exhibits "treading" movements of the hind legs, and seems unusually affectionate. She spends a good deal of time rolling on the floor and seems much more restless than usual. The cat's voice seems more piercing than usual and she may "call" for 1-2 days before she accepts the male.
 

The term gestation means the period when the young are developing in the mother's uterus. In cats, gestation normally lasts 63-65 days. Siamese cats may carry their kittens for 67 days.

Diagnosis of Pregnancy

There are no practical blood or urine tests available for early diagnosis of pregnancy in the cat. The earliest possible time of diagnosis may be at 3-4 weeks after breeding, when the doctor may be able to detect pregnancy by feeling the abdomen.

Physical Changes

During the first 4-5 weeks of pregnancy, there are few noticeable changes.
Weight gain and enlargement of the abdomen generally become noticeable after the fifth week. The increase, of course, varies with the size of the litter.
The mammary glands may begin to enlarge during the fifth week, but typically no increase in size is noticed until the seventh week. Milk is normally present 1-2 days before delivery.

Behavioral Changes

During the last weeks of pregnancy, your cat may have difficulty finding a comfortable position and may seem restless. Many queens (female cats) seek seclusion. Occasionally the cat may soil the house because the heavy uterus is pressing the bladder or colon.

Exercise

Normally no restriction of exercise is required during the first 6-7 weeks.
Your cat should be kept in the house during the last 2 weeks because she may attempt to have her kittens in an unsafe outside location.

Nutrition

Good nutrition is essential to the health of both mother and kittens. It is nearly impossible to overfeed a pregnant cat, since she requires 2-4 times as much food as normal.

Harmful feeding practices include feeding raw egg whites, raw fish and exclusive meat or fish diets. Your doctor may prescribe a special diet or supplementation.
 

Are You Ready for Newborn Kittens?

Whether your ready for baby kittens may not be the question. If your cat is, you have no choice but to get prepared, unless you want the corner of your closet and extra bedding to become part of the new kitten experience. Cat inevitably choose their own spot but can be enticed to a mutual location with some kitten and cat comforts in mind. You also want to make sure birthing goes smoothly for the health of your cat, so information and preparation is key.

Preparation for Delivery

You should begin to prepare for birth of the kittens before the queen gives birth. A box should be provided so that the mother becomes accustomed to sleeping in it and will deliver the kittens there. Most cats prefer a covered delivery box. Food and water can be kept nearby. Place the box in a secluded yet familiar area of the home, away from family traffic, to allow mother and kittens solitude and rest. Newspapers make excellent bedding because they can be changed easily, are absorbent, and can be shredded by the mother as she makes her "nest." If such materials as old quilts, rugs, blankets or mattress pads are used, they should be laundered frequently.

If you want to know more precisely when delivery is near, check the rectal temperature twice daily, starting on the 60th day. Rectal temperature drops below 100 F within 24 hours before the onset of labor. Normal rectal temperature ranges from 100.5 to 102 F.

Labor and Delivery

During the first stage of labor, the mother cat (queen) seems uneasy and restless. She may refuse food or water. The cat's rectal temperature drops, and she seeks dark, secluded places. Considerable howling may occur. This stage lasts 12-24 hours.

In the second stage, contractions and expulsion of the kittens begin.
Delivery starts with a small, greenish sac protuding from the vaginal opening. This is followed by a kitten and the attached placenta. The normal presentation of the kitten is nose first, lying on its abdomen. Some kittens, however, are born hindquarters first. After the delivery, the mother normally opens the sac by licking and biting, cleans off the kitten and severs the umbilical cord. You may have to perform these functions for the mother if she refuses to do it herself (see Obstetric Care below). Make sure the sac is removed from the kitten immediately if the mother doesn't do so.

The third stage of labor is a resting stage, which follows delivery of each kitten. This stage may last from a few minutes to one hour. Occasionally, 2 kittens are delivered within a few minutes, followed by resting.

Obstetric Care

After each kitten is born, remove all membranes covering the kitten, clean off its face, and remove mucus from its nose and mouth. Rub the kitten with a clean, dry towel to dry it and to stimulate breathing and circulation.
After a few minutes of rubbing, the kitten should begin to squirm and cry.
The umbilical cord should be tied about 1 inch from the body with fine thread and cut on the side of the knot away from the kitten. Apply a drop of iodine or merthiolate to the cord end after it is cut.

Assisting with the Birth

If a kitten seems to be lodged in the birth canal and the mother cannot expel it, assistance is necessary. There may not be time to call your veterinarian and drive to the hospital if you wish to save the kitten. Grasp the kitten with a clean towel and exert steady, firm traction. Do not jerk or pull suddenly. The best place to grasp the kitten is by the skin of the back, but gentle traction on the legs may be necessary.

Notify the Doctor if Any of the Following Occur:

* You cannot remove a kitten lodged in the birth canal.

* Labor is strong and persistent for 30 minutes without a birth.

* Labor is weak and intermittent for 5 hours without any results.

* There is a dark vaginal discharge, and no labor or births have occurred within 3-4 hours.

* The pregnancy lasts more than 67 days.