Pregnancy in Dogs

How long is a female dog in heat?

The age of sexual maturity depends on the breed: earlier in small breeds (from 6 months), later in large breeds (up to 18 months). Being sexually mature does not yet mean the dog is ready for a pregnancy: the birth canals have not fully matured during the first heat cycles.

A female dog usually goes into heat every six months. During the heat, the vulva receives more blood flow and secretes a bloody fluid. About two days before ovulation, she becomes ready for mating.

During the actual ovulation phase, the vaginal discharge becomes clearer and more mucous-like: this makes mating easier. At the same time, the progesterone level rises, preparing the body for pregnancy.

Recognizing the signs of pregnancy

Many owners first notice the pregnancy through small behavioral changes, even before the belly visibly grows. The signs differ depending on the phase.

Early phase: week 1 to 3

In the first three weeks, there is hardly anything to notice from the outside. The dog sleeps more than usual, withdraws more often, and seems calmer. Her appetite fluctuates: some dogs eat a little less at first, while others already show more hunger now.

Some dogs feel nauseous in the early phase, similar to humans in the first trimester. This is normal and usually passes after one to two weeks. If your dog isn't eating at all or is vomiting, a quick call to the vet is worth it.

Middle phase: week 4 to 5

From the fourth week, the first physical signs become visible. The teats grow larger and turn pink to dark pink. Hair may fall out around the teats. From day 30, a clear or whitish mucus emerges from the vagina.

From week 5, the visible weight gain begins. At this point the vet can palpate the embryonic sacs by feel, if the timing of the exam is right.

Late phase: from week 6 on

Now the pregnancy is clearly recognizable, even to a layperson. The belly is distinctly rounded, the mammary glands keep swelling. The appetite increases noticeably. In this phase, many dogs start nesting behavior: they scratch, carry blankets around, or look for quiet corners.

How does the vet detect a pregnancy?

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

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, and after day 30 they fill up so much that they become harder to tell apart. The method depends heavily on the vet's experience and the dog's body shape.

Ultrasound

Ultrasound is the most common method. From day 18, the first heartbeats may be visible, and the diagnosis becomes reliable from day 25. Ultrasound shows the number of embryonic sacs and checks the embryos' heart activity, but it does not give an exact puppy count.

X-ray

Only from day 45 are the puppies' skeletal bones fully calcified and visible on an X-ray. This makes the X-ray the only method that can determine the exact number of puppies. This information matters: the person assisting the birth needs to know whether all the puppies have left the womb.

Relaxin test

The hormone relaxin is produced only during a real pregnancy. From day 24 after fertilization, a positive result is possible. The relaxin test is the only method that reliably distinguishes between a real pregnancy and a false pregnancy.

How long does the pregnancy last?

The pregnancy lasts 61 to 65 days, depending on the timing of ovulation. Because sperm can survive 6 to 10 days in the uterus, the length varies based on when mating took place. Early mating can extend the pregnancy to up to 72 days. With a normal course, the expected due date falls around day 63 after mating.

The pregnancy week by week

Week 1 to 2

Fertilization takes place, but the dog still shows no symptoms. The eggs are fertilized and travel toward the uterus. Nothing on the outside hints at a change.

Week 3

The embryos implant. The dog becomes calmer and sleeps more. Some show mild nausea or eat irregularly. The relaxin test is still too early in this phase.

Week 4

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

Week 5

The belly starts to bulge. The dog now needs more energy: from this week on, gradually switch to puppy food. The puppies are recognizable as tiny beings on an ultrasound, and movements are visible.

Week 6

The puppies' body movements become noticeable. The mammary glands grow clearly larger and the dog drinks more. Activity decreases. Keep walks shorter, but offer them several times a day.

Week 7

The belly is very large and the dog seems sluggish. Nesting behavior sets in. Set up the whelping box now and let her get used to it. From day 45 the X-ray is possible to determine the number of puppies.

Week 8

The puppies move into the birthing position. Colostrum forms in the teats. Daily measuring of the body temperature begins. A temperature drop below 37 °C signals that birth will begin in 12–24 hours.

Week 9: Birth

Labor sets in. The dog is restless, pants, and scratches. A clear vaginal discharge indicates that the first puppy is on its way. It should arrive within the next 20–30 minutes.

Nutrition during pregnancy

Proper feeding is one of the most common questions vets hear from soon-to-be puppy owners. The good news: little changes until the fifth week.

Week 1 to 5: Normal maintenance food

In the first four to five weeks, the amount of food stays the same. The energy demand barely rises during this phase, while overfeeding can instead strain the dog's health. High-quality food that she has tolerated well so far is the best choice.

From week 5: Gradual switch

From the fifth week, the energy demand rises by 30 to 50%. Small dogs with few puppies need about 30% more, while large dogs with many puppies need up to 50% more. It makes sense to switch to a puppy food for pregnant and lactating dogs: it contains more protein and a higher energy density.

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

The last week and the day of birth

In the last week before birth, the dog often eats little to nothing. On the day of birth itself, she often refuses the meal entirely. This is normal and no cause for concern.

Lactation: about 2 to 3 times the normal demand

During the nursing phase, the energy demand is at its highest. For each puppy, it rises by about 25%. With a litter of six puppies, that means about 2 to 3 times the normal amount of food. As soon as the puppies start eating supplementary food, gradually reduce the mother's portion.

Calcium: please do not supplement

A common mistake is giving extra calcium during pregnancy. It sounds sensible, but it can do the opposite: too much calcium during pregnancy raises the risk of eclampsia (milk fever) after birth. The reason is that with a constantly high calcium supply, the body dials down its own calcium regulation. Avoid calcium supplements during pregnancy unless the vet explicitly recommends them.

What you can do

Stay calm

Birth is an extremely stressful affair for the dog: extra restlessness from the people around her puts even more strain on her. Intervene as little as possible during the birth, but stay nearby so you can act immediately in case of complications.

Prepare the whelping box

From day 40, prepare a whelping box: a cardboard or wooden box. Large enough for the dog and the puppies, with room to spare for the mother. High enough that the puppies can't escape. A quiet, warm spot without drafts. In the first week, the puppies need an ambient temperature of 28–32 °C.

Place the dog's bed in or next to the box. A few toys help her accept the box as a safe place. Keep bed sheets, covers, or towels handy for the birth.

Switching the food

In the first 5 weeks of pregnancy you can keep feeding normal food. From week 5, switch to food for pregnant and lactating dogs.

Rule of thumb for dosing:

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

Feed two to three times a day, always with enough drinking water. In the last week before birth and on the day of birth itself, the dog may eat little to nothing: this is normal.

During the nursing phase: increase the energy demand by 25% per puppy. As soon as the puppies start eating supplementary food, gradually reduce the mother's ration.

Documenting the temperature

From the first third onward, measure the temperature rectally: ideally enter it in a diary every day. This way changes can be spotted early. The vet will show you the right measuring technique.

Document the following: body temperature, due date, onset of labor, birth times of the individual puppies, and the number, sex, and weight of the puppies, plus the ambient temperature. To tell the puppies apart at first, tie a little ribbon with names or numbers on each one.

The 5 phases in brief

Shortly before birth

From ten to six days before the due date, measure the body temperature daily. Normal: 37–38 °C. Shortly before birth, it drops to 36.5–37 °C.

Other signs of an approaching birth:

• Frequent urination
• Licking the vulva
• Nesting behavior
• Loss of appetite
• Restlessness, trembling, or panting
• Scratching on the floor or in the dog bed

Birth

The contractions are clearly recognizable: the dog secretes a clear discharge. The first puppy should arrive within the next 20–30 minutes. Between puppies there are usually 20 minutes, but it can also take more than an hour. If the rest phase lasts longer than two hours, contact the vet immediately.

The dog cuts the umbilical cord herself, frees the puppies from the amniotic sac, and licks them: this stimulates their breathing. After each puppy comes an afterbirth. As a rule, the dog eats it, since it contains a lot of protein and nutrients.

After birth

The dog cleans herself first, then lies on her side and stretches out her legs. The puppies drink the colostrum: the first milk. It contains 95% of the antibodies for the puppies' immune system, stimulates their first bowel movement, and is yellowish and a little stickier than the milk that comes later.

Complications: when to go to the vet right away?

Most births go smoothly. Even so, medical help can become necessary. The following situations call for an immediate phone call:

• Green vaginal discharge before the first puppy is born
• Foul-smelling discharge at any point
• The dog actively pushes for longer than 20–30 minutes without a puppy arriving
• After one puppy is born, the next one does not come within two hours
• A fever above 39.5 °C after birth
• The dog is apathetic, can't stand up, or trembles heavily
• Cramps or muscle twitches (possible eclampsia)

What is eclampsia?

Eclampsia is a calcium-deficiency emergency that occurs mainly in the first three weeks of lactation. The dog shows cramps, trembling, stiffness, or unconsciousness. The cause is a too-rapid loss of calcium through the milk. Without immediate treatment by the vet, eclampsia can be fatal.

C-section: when is it necessary?

A C-section needs to be planned in advance for certain breeds: bulldogs, pugs, and other brachycephalic breeds often have such a large head that a natural birth is anatomically difficult or impossible. Beyond that, it becomes necessary when labor doesn't lead to a birth within two hours, or when a puppy is stuck in the birth canal. Only the vet decides whether it is indicated.

Keep the vet's phone number handy

Female dogs usually manage the birth on their own without trouble: but complications can occur. Keep the vet's emergency number ready (including for nighttime).

False pregnancy: when the body simulates a pregnancy

Four to nine weeks after a heat, dogs that aren't pregnant can develop a false pregnancy. The phenomenon is more common than many owners think.

What happens in the body?

After the heat ends, the progesterone level drops rapidly. In some dogs, the body registers this drop as a "birth" and raises the prolactin level. Prolactin stimulates the mammary glands. The result: milk production without puppies.

What symptoms does the dog show?

• Milk forming in the teats
• Nesting behavior (dragging around toys, blankets, shoes)
• Mothering toys or other objects
• Restlessness, changes in appetite
• In rare cases, aggression toward other animals or people who come near the "nest"

What helps?

Most false pregnancies resolve on their own within two to three weeks. Remove the toys the dog is "mothering": this won't prolong the behavior unnecessarily. Distraction through walks and activity helps. Don't use the food withdrawal that some books recommend: it leads to unnecessary stress.

Go to the vet if the symptoms last longer than three weeks, if the dog shows physical complaints (mastitis, fever), or if the aggression becomes a problem. The vet can shorten the behavior with hormones or other means. The relaxin test quickly clarifies whether it's a real or a false pregnancy.

Puppies in the first eight weeks

Week 1 and 2: The mother handles everything

In the first two weeks, the puppies are blind and deaf. They alternate between sleeping and drinking. The mother warms them, cleans them, and stimulates digestion by licking. You only observe, check the weight daily, and make sure all the puppies are nursing.

Normal weight gain: doubling within the first ten days. A puppy that isn't gaining weight or is lying off to the side needs attention right away.

Week 3 and 4: Eyes and ears open

From day 10 to 14, the eyes open, and around day 18 the ears follow. The puppies start their first attempts at walking. From week 4 you can offer supplementary food: softly soaked puppy food or a special mush. Mother's milk remains the main source of nutrition.

Week 5 and 6: Socialization begins

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

Week 7 and 8: Preparing for rehoming

The puppies now eat on their own. The mother sets limits during nursing and weans the puppies naturally. By eight weeks, all the puppies should have been examined by a vet, vaccinated, and dewormed. Puppy training begins from the first day in the new family.

Preventing pregnancy

Anyone who doesn't want puppies has several options.

Spaying

The safest and most permanent method. For female dogs, the vet recommends the right timing depending on the breed and stage of development. Benefits: no risk of an unwanted pregnancy, and often a reduced risk of certain tumors and uterine diseases.

Hormonal contraception

A hormone treatment (progesterone preparations) can prevent the onset of the heat or suppress the readiness to mate. It is only recommended in exceptional cases because of an increased risk of uterine diseases. If at all, then only under veterinary supervision.

Emergency treatment after mating

If the dog had unwanted contact with a male, the vet can start a treatment within a few days that prevents the embryos from implanting. This option is time-critical and available only from the vet.

You'll find every topic around dog care at Hundeo Pro. From training and nutrition to health: structured courses with video instructions, training tracking, and personal help from real trainers when problems come up.