Pregnancy and Labor in Cats

By Courtney Barnes, BSc, DVM; Krista Williams, BSc, DVM, CCRP; Ernest Ward, DVM

Breeding cats can be an extremely rewarding experience. However, before undertaking a breeding program, it is essential to understand what this involves, from the time of mating to the time of weaning.

It is also important to remember that overpopulation contributes to millions of unwanted cats being euthanized yearly. It will be your responsibility to find permanent, loving homes for every kitten.

What happens when my cat comes into heat?

Queens (intact female cats) come into heat (estrus) many times a year. Cats in estrus become very affectionate and vocal, demanding attention and rolling frequently. When stroked, they raise their rear quarters and tread the ground with their back legs. These behavioral changes can confuse an inexperienced owner, who may interpret the behavior as a sign of pain or illness. The pattern of estrus is variable from cat to cat and is usually seasonal.

What will mating my cat involve?

A queen is an induced ovulator, meaning her eggs are released from her ovaries in response to mating or sexual contact. During mating, the male cat holds the queen's scruff in his teeth and when he ejaculates, the queen cries out and frequently becomes aggressive. Although it appears violent, this is normal mating behavior. After mating, she will groom herself, wait a while, and then mate again. Pregnancy or gestation ranges from 60–67 days, averaging 63–65 days.

Will my cat's diet need to be changed during pregnancy?

During pregnancy, the queen's nutrient requirements will reach one-and-a-half times her pre-pregnancy level. By the time of weaning, it may exceed twice the pre-pregnancy level. It will be necessary to increase the number of meals given and feed a diet formulated for pregnant females or kittens, to provide the additional nutrients required for pregnancy and nursing.

Will my cat's behavior change during pregnancy?

During pregnancy, the cat's behavior alters very little, although some cats become more loving, and a few become aggressive. During the final week, the queen may search for a suitable kittening bed or nest. The pregnant cat should be confined indoors at this time. It is important that you are able to monitor your cat closely to witness any complications.

What preparations are needed before my cat has her kittens?

The kittening bed can take many forms, but a cardboard box lined with newspaper, old sheets, or towels is ideal. The bed should be warm, cozy, and private, but must be observable. It can be helpful to know how many kittens your cat is carrying, so you know for certain when all the kittens have been born. This can be done by your veterinarian. At around day 45 of pregnancy, the fetal skeletons can be visible on X-ray for counting.

What are the stages in labor?

First stage labor is essentially the relaxation of the cervix and vagina and the start of intermittent contractions in the uterus. The pelvic muscles slacken, and the area between the anus and the vulva (the perineum) becomes looser and longer. At this stage, the uterine contractions are not yet visible as straining, although you may see or feel movement of the fetuses through the abdominal wall. The cat will often make repeated visits to the kittening bed, and many cats will desire reassurance from the owner. Scratching and bed-making may be evident, and some cats may begin to pant.

"The queen usually stops eating during the last twenty-four hours before labor..."

The queen usually stops eating during the last twenty-four hours before labor, and her temperature may drop below 100°F (37.8°C). Vaginal discharge is rarely seen. In many cats having their first litter, this first stage of labor can last up to 36 hours.

In second stage labor, the uterine muscle begins stronger and more frequent contractions. As each fetus enters the pelvis, the outer layer of its membranes appears briefly at the vulva as the water bag which will burst open. The inner membranes remain on the fetus and act as a lubricant to assist its passage.

As the fetal head passes into the pelvis, its pressure causes voluntary straining using the abdominal muscles. This bearing down helps to move the fetus through the pelvis. This is usually the point at which the attendant can see that the cat is actively straining. Normally, delivery of a kitten from the commencement of the second stage may take from five to thirty minutes. Once the head is out of the vulva, one or two more contractions should complete the passage of the narrower remainder of the kitten's body.

Third stage labor follows immediately and is simply the passage of the fetal membranes, complete with the greenish black mass of separated placenta or "after-birth". A set of membranes is normally passed immediately after each kitten, although sometimes a second kitten will follow so quickly that the membranes from the first will be delayed temporarily. As each kitten is born, the mother will tear open the membranes and clear the mouth and nose area of the kitten, bite off the umbilical cord, and subsequently eat the afterbirth.

Intervals between kitten births are variable. On average, the intervals last ten minutes to an hour.

So-called interrupted labor is sufficiently common in the cat to be considered a normal occurrence. In this case, the queen stops straining, rests happily, suckles those kittens already born and accepts food, despite still having more kittens to deliver. This resting stage may last twenty-four or even up to thirty-six hours, after which straining recommences and the remainder of the litter is born normally.

Owners should observe the birthing process closely but should not upset the queen by interfering any more than absolutely necessary. Most cats deliver their kittens without complications; however, first-time mothers should be attended by their owners. Once all the kittens are born, the dirty bedding can be removed and replaced.

What problems can arise during birth?

Dystocia or difficult birth can occur. You should be concerned and immediately seek veterinary attention if:

  • Twenty minutes of intense labor does not produce a kitten.
  • Ten minutes of intense labor does not expel a kitten that can be seen at the queen's vulva.
  • Gentle pulling on a trapped fetus causes the queen pain.
  • The queen is depressed, lethargic, or has a fever (rectal temperature greater than 103°F or 39.4°C).
  • The queen loses fresh blood from her vulva for more than ten minutes.

How do I revive a non-responsive newborn kitten?

  • Tear the membranes from the nose, wipe the nose, open the mouth, tilt the kitten's head down and clear away any fluids.
  • If the umbilical cord has not broken on delivery, tear it an inch from the kitten and remove the bulk of the membranes. Complicated cutting and tying of the cord are unnecessary. The queen would chew through it, providing a blunt crushing action to prevent bleeding; you can do the same thing by tearing it between your first two fingers and thumb.
  • If the kitten is not breathing, or if it was delivered tail first and possibly inhaled fluid, it is necessary to clear debris and fluid from the air passages The back of the mouth can be suctioned using a pediatric bulb syringe or Argyle™ DeLee mucus trap to clear away fluids while the kitten is rubbed vigorously. “Swinging” kittens to remove fluid is no longer recommended as it can cause severe brain trauma. The color of the kitten's tongue is a reliable indicator of success. If the kitten is receiving sufficient oxygen, the tongue will be pink, if not it will have a bluish tint.
  • Next, stimulate breathing by briskly stroking and rubbing the kitten with a clean, dry towel. If the kitten begins breathing regularly continue to dry it off briskly with the towel. If it is not breathing, some further form of artificial respiration may be necessary. Mouth to mouth resuscitation is probably the most useful if carried out carefully. 
  • There are several essential points to remember.
      • First, you should never blow fluids and debris further down the respiratory tract; you must first clear away these secretions by suction.
      • Second, the capacity of kitten lungs compared to humans' is quite tiny. Blow small puffs of air into the mouth very gently and allow a pause for expiration. 
      • Repeat this cycle every three to five seconds. Ideally, use a short drinking straw to blow through since this is more hygienic and reduces the risk of damaging the kitten's lungs by over-inflation.

Where should I put the newborn kittens?

Warmth is essential for the newborn. Kittens cannot control their own body temperature for the first couple of weeks of life. In nature, kittens stay warm by direct body contact with their mother and littermates in the enclosed nest bed. A wet newborn kitten loses heat very rapidly, so it is very important to make sure it dries off quickly. If the queen is ill or uncooperative, gently lay the kitten on a warm, towel-wrapped hot water bottle and conserve its body heat by covering it with a blanket. Great care must be taken not to inflict contact burns by having the bottle too hot.

Ideally, the temperature in the box should be maintained at 85-90°F (29.4-32.2°C) during the first four days of life. The temperature can be gradually reduced to 80°F (26.7°C) by seven to ten days and to 72°F (22.2°C) by the end of the first month. If you cannot maintain the room temperature this high, an acceptable alternative is a heat lamp suspended over the nest box. Disadvantages to a heat lamp are that many cats dislike the open bed required for its use, which may make both mother and kittens too hot, and lessen their normal close contact. The box should be large enough for the kittens to move away from the heat if they become too hot.

Do I need to help my cat raise her kittens?

Occasionally, kittens will be born prematurelyThey will be small, thin, and have little or no hair. These kittens require intensive nursing care. Premature kittens often fail to nurse, and need to be fed with a syringe, bottle, or stomach tube.

They also need to be kept warm if the queen rejects them.

A normal healthy kitten, when warm and dry, needs no assistance in finding its mother's teat and suckling. Occasionally, an exhausted, restless, nervous, or ill queen may fail to assist her kittens. If the queen fails to nurse her kittens, she should be checked by your veterinarian. If the mother is unable to care for the kittens, they may need to be hand fed (see the handout “Raising Kittens”).

Are there any post-birthing complications I may need to know about?

Yes. These include retention of fetal membranes (afterbirth/placenta), metritis, mastitis, and eclampsia (milk fever).

Retention of Fetal Membranes. Occasionally, a cat may fail to pass the final set of fetal membranes after birth is complete, and they will decompose within her uterus. If this occurs, the queen often shows signs of restlessness and abdominal discomfort and may be unwilling to settle with her kittens. Her appetite may be poor, and a brownish vaginal discharge may be seen. Immediate veterinary care is required, and an examination will show an elevated body temperature, while palpation of her abdomen will reveal an enlarged uterus. Antibiotic treatment is necessary and other medications may be necessary to cause the expulsion of the retained membranes.

Metritis or Endometritis. Metritis and endometritis are different types of inflammation of the uterus that usually occur within three days of labor (parturition). The cat is much more obviously ill than with retention of fetal membranes. She will be dull and lethargic, completely ignore her kittens, and refuse food. She may have an increased thirst and may vomit. There will be a purulent, foul-smelling discharge from her vagina, and she will have a fever. On palpation, the abdomen is tender, and the uterus is thickened. Immediate veterinary intervention is required.

Mastitis. Mastitis or inflammation of a mammary gland sometimes occurs during early lactation. It is usually confined to one gland. The affected gland will be firm, hot, painful, and enlarged. If the condition is caused by congestion, the application of gentle heat and subsequent gentle massage will bring normal milk out of the teat orifice, and the situation may be speedily relieved by milking the gland concerned. If an infection is present, in addition to pain and swelling in the gland, there may be a colored discharge from the nipple and the cat will have appetite loss (anorexia), be lethargic, and feverish. If an abscess has formed, there may be a purplish area of accumulated pus. Mastitis requires immediate veterinary treatment.

Eclampsia or Milk Fever. In cats, milk fever (also called eclampsia or lactation tetany) may occur three to five weeks after the birth of kittens and is due to a sudden drop in the amount of calcium circulating in the bloodstream, associated with the heavy demands of milk production. The affected cat is usually nursing a large litter. The first signs of milk fever include restlessness, panting, muscle tremors, and incoordination. It can progress to tetanic (or rigid, stiff-legged) muscular spasms, followed by convulsions or coma. If you suspect that milk fever is developing, immediately stop the kittens from suckling and seek veterinary care for this life-threatening condition. Treatment with intravenous injections of calcium preparations leads to a spectacular reversal of the condition. A later subcutaneous injection may be required to maintain the recovery. Kittens should be removed from the cat if old enough; otherwise, they should be given supplementary feeding. Any affected cat should only be allowed to rear a small number of kittens at any subsequent litter. Since lactation tetany often recurs with subsequent litters, it should factor into any decisions about further breeding of an affected queen.

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