Dog Pregnancy

How long is a bitch in heat?

Sexual maturity depends on the breed: small breeds reach it earlier (from 6 months), large breeds later (up to 18 months). Sexual maturity does not mean the bitch is ready for pregnancy: the birth canals are not yet fully developed in the first heat cycles.

A bitch usually comes into heat every six months. During heat, the vulva becomes more perfused and secretes a bloody fluid. About two days before ovulation, she becomes ready for mating.

During the actual ovulation phase, vaginal discharge becomes clearer and more mucous: this facilitates mating. At the same time, progesterone levels rise, preparing the body for pregnancy.

Recognizing signs of pregnancy

Many owners first notice pregnancy through small behavioral changes, before the belly becomes visibly larger. The signs differ by phase.

Early phase: weeks 1 to 3

In the first three weeks, very little is visible from the outside. The bitch sleeps more than usual, withdraws more often, and seems calmer. Appetite fluctuates: some bitches eat slightly less at first, others show increased hunger from the start.

Some bitches experience nausea in the early phase, similar to first-trimester morning sickness in humans. This is normal and usually passes within one to two weeks. If the bitch stops eating entirely or vomits repeatedly, a quick call to the vet is worthwhile.

Middle phase: weeks 4 to 5

From week four, the first physical signs appear. The teats enlarge and turn pink to dark pink. Hair around the teats may fall out. From day 30, a clear or whitish mucus discharge from the vagina is normal.

From week 5, visible weight gain begins. The vet can palpate the embryonic sacs during this window if the timing is right.

Late phase: from week 6

Now pregnancy is unmistakable even to the untrained eye. The belly is visibly rounded, the mammary glands continue to swell. Appetite increases noticeably. Many bitches begin nesting behavior: scratching, dragging blankets, seeking quiet corners.

How does the vet diagnose pregnancy?

Four methods are available, each with its own time window and reliability.

Palpation

The vet can feel the embryonic sacs through the abdominal wall from day 21 to 30. This window is narrow: before day 21 the sacs are too small, after day 30 they fill and become harder to distinguish individually. Results depend heavily on the vet's experience and the dog's build.

Ultrasound

Ultrasound is the most common method. Heartbeats may be visible from day 18; reliable diagnosis from day 25. Ultrasound shows the sacs and checks fetal heartbeats but does not give an exact puppy count.

X-ray

Only from day 45 are the puppies' skeletal bones calcified enough to appear on X-ray. This is the only method that gives an exact puppy count, important information for the birth attendant to know when all puppies have been born.

Relaxin test

The hormone relaxin is produced exclusively during a real pregnancy. A positive result is possible from day 24 after fertilization. The relaxin test is the only method that reliably distinguishes a real pregnancy from a false one.

How long does pregnancy last?

The gestation period is 61 to 65 days, depending on when ovulation occurred. Because sperm can survive in the uterus for 6 to 10 days, duration varies with the mating date. Early mating can extend pregnancy to up to 72 days.

Pregnancy week by week

Weeks 1 to 2

Fertilization takes place but the bitch shows no symptoms yet. Eggs are fertilized and travel toward the uterus.

Week 3

Embryos implant. The bitch becomes quieter, sleeps more. Some show mild nausea or irregular eating. The relaxin test is still too early at this stage.

Week 4

Organ development begins: heart, eyes, spinal canal. From day 24 the relaxin test is possible, from day 25 ultrasound. Teats grow larger and darker. A milky mucous discharge may appear.

Week 5

The belly begins to round out. Energy needs increase: start transitioning to puppy food now. Puppies are recognizable on ultrasound as small figures, and movement is visible.

Week 6

Puppy movements become palpable. The mammary glands enlarge noticeably, the bitch drinks more. Activity decreases. Keep walks shorter but offer them several times a day.

Week 7

The belly is very large, the bitch moves slowly. Nesting behavior starts. Set up and introduce the whelping box now. From day 45, X-ray is possible to determine the puppy count.

Week 8

Puppies move into birth position. Colostrum forms in the teats. Daily temperature measuring begins. A drop below 37 °C signals that birth will begin within 12 to 24 hours.

Week 9: Birth

Labor begins. The bitch is restless, pants, scratches. Clear vaginal discharge signals that the first puppy is on its way. The first puppy should arrive within 20 to 30 minutes.

Nutrition during pregnancy

Weeks 1 to 5: Normal maintenance food

For the first four to five weeks, the food amount stays the same. Energy needs barely increase during this phase, and overfeeding can actually burden the bitch's health. Continue with whatever quality food she has been eating well.

From week 5: Gradual transition

From week five, energy needs increase by 30 to 50 percent. Small dogs with few puppies need about 30 percent more; large dogs with many puppies up to 50 percent more. Switching to puppy food designed for pregnant and lactating bitches makes sense: it contains more protein and higher energy density.

Split meals into two to three smaller portions. In the last two weeks, the puppies compress the stomach so much that smaller, more frequent meals are better tolerated than one large serving.

Last week and birth day

The bitch often eats little or nothing in the final week before birth. On the day of birth she frequently refuses food entirely. This is normal and no cause for concern.

Nursing: about 2 to 3 times normal intake

Energy needs peak during the nursing phase. Each puppy adds roughly 25 percent to the daily requirement. With a litter of six puppies, that means about 2 to 3 times the normal food amount. Once puppies start eating solid food, gradually reduce the mother's portion.

Calcium: do not supplement

A common mistake is adding extra calcium during pregnancy. It sounds logical but can backfire: too much calcium during pregnancy raises the risk of eclampsia (milk fever) after birth. The body downregulates its own calcium control when supply is constantly high. Avoid calcium supplements during pregnancy unless the vet specifically recommends them.

What you can do

Stay calm

Birth is extremely stressful for the bitch: added restlessness from owners makes things harder. Interfere as little as possible during birth, but stay nearby to act immediately if complications arise.

Prepare the whelping box

From day 40, prepare a whelping box: cardboard or wood. Large enough for the bitch and puppies, with room for the mother to rest alone. High enough so puppies cannot climb out. Choose a quiet, warm spot without drafts. Puppies need 28 to 32 °C ambient temperature in the first week.

Place the bitch's bed in or next to the box. A few toys help her accept it as a safe space. Keep sheets, covers, or towels ready for the birth.

Diet change

Normal food for the first 5 weeks of pregnancy. From week 5, switch to food for pregnant and lactating bitches.

Rule of thumb:

• Small dogs with few puppies: increase energy intake by 30 percent
• Large dogs: increase energy intake up to 50 percent

Feed two to three times a day, always with plenty of fresh water. In the last week before birth and on the birth day itself, the bitch may eat very little or nothing: that is normal.

During nursing: increase energy by 25 percent per puppy. Once puppies start eating supplementary food, gradually reduce the mother's portion.

Record temperature

Start measuring temperature rectally from the first trimester, ideally noting it daily in a journal. This makes changes easy to spot early. The vet can show you the correct technique.

Record: body temperature, due date, onset of labor, birth times of individual puppies, number, sex and weight of puppies, ambient temperature. To tell puppies apart, tie a ribbon with a name or number on each.

When to call the vet immediately

Most births go smoothly. These situations require an immediate call:

• Green vaginal discharge before the first puppy is born
• Foul-smelling discharge at any point
• The bitch pushes actively for more than 20 to 30 minutes without a puppy arriving
• More than two hours pass after one puppy without the next
• Fever above 39.5 °C after birth
• The bitch is lethargic, cannot stand, or shivers heavily
• Convulsions or muscle twitching (possible eclampsia)

What is eclampsia?

Eclampsia is a calcium-deficiency emergency that occurs most often in the first three weeks of nursing. The bitch shows convulsions, trembling, stiffness, or loss of consciousness. It is caused by calcium being lost too rapidly through milk. Without immediate veterinary treatment, eclampsia can be fatal.

When is a caesarean section necessary?

For some breeds, a c-section should be planned in advance: bulldogs, pugs, and other brachycephalic breeds often have heads too large for natural delivery. Beyond that, a c-section is indicated when two hours of active labor produce no puppy, or when a puppy is stuck in the birth canal. Only the vet makes this call.

False pregnancy: when the body mimics pregnancy

Four to nine weeks after heat, non-pregnant bitches can develop a false pregnancy. This is more common than many owners realize.

What happens in the body?

After heat ends, progesterone levels drop rapidly. In some bitches, the body interprets this drop as a birth and raises prolactin levels. Prolactin stimulates the mammary glands. Result: milk production without puppies.

What symptoms does the bitch show?

• Milk production in the teats
• Nesting behavior (carrying toys, blankets, shoes)
• Mothering toys or other objects
• Restlessness, appetite changes
• Occasional aggression toward animals or people who approach the "nest"

What helps?

Most false pregnancies resolve on their own within two to three weeks. Remove toys the bitch is mothering: it does not prolong the behavior to leave them out. Distraction through walks and activities helps. Do not withhold food: it only adds unnecessary stress.

See the vet if symptoms last more than three weeks, if the bitch shows physical discomfort (mastitis, fever), or if aggression becomes a problem. The vet can shorten the episode with hormones or other treatments. A relaxin test quickly confirms whether it is a real or false pregnancy.

Puppies in the first eight weeks

Weeks 1 and 2: Mother handles everything

Puppies are blind and deaf in the first two weeks. They alternate between sleeping and nursing. The mother warms, cleans, and stimulates digestion by licking. The owner observes, checks weight daily, and makes sure all puppies are nursing.

Normal weight gain: doubles within the first ten days. A puppy that is not gaining weight or lying apart from the litter needs immediate attention.

Weeks 3 and 4: Eyes and ears open

Eyes open between days 10 and 14; ears follow around day 18. Puppies begin their first attempts at walking. From week 4, supplementary food can be offered: softened puppy food or special puppy porridge. Mother's milk remains the main food source.

Weeks 5 and 6: Socialization begins

The most important window for future social compatibility: puppies now imprint on people, other dogs, and sounds. Positive experiences in this phase last a lifetime. Regular, gentle contact with different people is more valuable now than any later training.

Weeks 7 and 8: Preparing for rehoming

Puppies eat independently now. The mother sets limits during nursing and weans naturally. By eight weeks, all puppies should be examined by a vet, vaccinated, and dewormed. Puppy training begins from day one in the new home.

Preventing pregnancy

Spaying

The safest and most permanent method. The vet recommends the right timing based on the breed and stage of development. Benefits: no risk of unwanted pregnancy, often also reduced risk of certain tumors and uterine disease.

Hormonal contraception

Progesterone preparations can prevent heat or suppress readiness to mate. They are rarely recommended due to an elevated risk of uterine disease, and only under veterinary supervision when used at all.

Emergency treatment after mating

If the bitch had unintended contact with a male, the vet can initiate treatment within a few days to prevent embryo implantation. This option is time-critical and available only from a vet.