How Soon Can You Determine Pregnancy In Dogs?

This article will cover the different signs and methods for determining if your dog is pregnant, and how early on these can be detected. We’ll go over physical signs and symptoms during pregnancy, medical tests to confirm pregnancy, behavioral indicators, and tips for preparing for a pregnant dog. Determining pregnancy early is important for proper prenatal care and ensuring the health of mom and pups.

Signs of Pregnancy

One of the earliest physical signs of pregnancy in dogs is their nipples becoming enlarged and pinker in color. This change usually occurs around 3-4 weeks into the pregnancy. The nipples will continue to grow as the pregnancy progresses. According to Purina, a dog’s teats will increase up to 1.5 times their normal size by the second half of pregnancy.

Weight gain is another obvious sign of pregnancy. Dogs will begin to gain weight rapidly about 4 weeks into the pregnancy as the puppies grow and take up more room. Expect your dog to gain 15-25% of her body weight by delivery. Make sure to feed her a high quality puppy food diet to support her nutritional needs (Purina).

As the pregnancy advances, your dog’s abdomen will enlarge noticeably. An enlarged or swollen belly that sags is a giveaway sign of pregnancy starting around 3-4 weeks in. Her shape will shift from an hourglass figure to a potbellied profile. Some swelling of the vulva may also occur as hormones increase and the dog’s body prepares for birth (South Seattle Vet).

Morning Sickness

Similar to human pregnancy, some dogs can experience “morning sickness” in the early stages of pregnancy, usually around 3-4 weeks along. This is caused by shifts in hormone levels like progesterone and estrogen. Signs of morning sickness in pregnant dogs include:

Appetite changes – Pregnant dogs may show a decreased appetite and reduced interest in food, especially in their usual favorite foods. Many lose their appetite entirely in the first few weeks. The decrease in appetite may be accompanied by nausea.

Vomiting – Some dogs will vomit occasionally, especially in the morning hours, due to nausea from hormonal changes. Usually the vomiting is mild and subsides after a few days or weeks.

Lethargy – Dogs may act tired and less energetic than usual. They may sleep more often and appear fatigued. This is likely connected to the appetite and gastrointestinal changes.

These symptoms of morning sickness typically last a few days or weeks and then dissipate as the dog’s body adjusts to the hormonal changes of pregnancy. Monitoring appetite and any vomiting is important, as pregnant dogs can become dehydrated. Speak to your vet if symptoms are severe or prolonged. Usually morning sickness is considered normal in early canine pregnancy.


Ultrasound is one of the most reliable ways to confirm pregnancy and monitor fetal development in dogs. According to VCA Animal Hospitals, an ultrasound can detect developing embryos as early as 3 weeks after breeding. However, the earliest a vet can clearly see the puppies on ultrasound is around 4 weeks into the pregnancy.

At 4 weeks gestation, the fetal poles will appear as little circles or blobs on the ultrasound screen. The heartbeats may be detectable with Doppler ultrasound by day 24-25. By 5 weeks, the puppy skulls are visible and the heartbeats should be easily seen.

Some key timeframes for what can be seen on canine pregnancy ultrasound according to East Central Veterinary Hospital are:

  • 4 weeks – Fetal poles visible
  • 5 weeks – Skulls and strong heartbeats visible
  • 6 weeks – Spines and ribs visible
  • 8 weeks – Fetal movement may be seen

So while pregnancy can’t be definitively ruled out until at least 4 weeks, the 4 week ultrasound is the first opportunity to clearly visualize the developing puppies. This early ultrasound is ideal for confirming pregnancy and estimating litter size before preparations for whelping begin.

Abdominal Palpation

One of the most reliable ways for a veterinarian to confirm pregnancy is through abdominal palpation, which is gently feeling the abdomen to detect changes in the uterus and presence of fetuses. This method can determine pregnancy as early as 4-5 weeks after breeding, which is when a veterinarian can start feeling the fetal swellings in the uterus (source). The fetus starts to calcify around day 28 but is too small to be detectable until about day 42-45 (source).

So between 4-5 weeks after breeding, an experienced veterinarian should be able to feel the presence of puppies in the uterus upon palpation. This examination requires no special equipment and allows the vet to estimate litter size and due date. It provides clear confirmation of pregnancy in dogs at a relatively early stage.

Relaxin Testing

One of the most common and accurate ways to confirm pregnancy in dogs is through testing for the relaxin hormone. According to the VCA Animal Hospitals, relaxin can be detected in the blood as early as 22-27 days after breeding. This hormone is produced by the developing placenta and helps relax the ligaments and pelvis in preparation for giving birth.

There are convenient at-home relaxin test kits like the Canine P4 Pregnancy Test that allow breeders to draw a blood sample themselves and get quick results without visiting the vet. These tests work by detecting elevated levels of relaxin in the blood that indicate pregnancy. The relaxin hormone offers a reliable way to diagnose pregnancy in dogs weeks before more obvious signs appear.


X-rays can be used later in a dog’s pregnancy to get an estimate of the number of puppies. Puppies generally become visible on x-rays around day 55 of the pregnancy ( Veterinarians will take x-rays from the side and above the abdomen to try and count the number of skulls and spines visible. This allows them to estimate the size of the litter.

X-ray counts are usually quite accurate, rarely off by more than one puppy. However, it is possible for a puppy to be hidden behind another on the x-ray, leading to a slightly lower count. X-rays can also sometimes identify if a puppy is in an abnormal position or if there are any abnormalities.

While x-rays provide helpful information, they do involve radiation exposure so vets will limit their use appropriately. X-rays are generally recommended between days 55-58 of gestation when the skeletons are more visible and there is less risk of harming the puppies (


One of the most notable signs of pregnancy in dogs is changes in their behavior. Around 4 weeks into pregnancy, dogs will start exhibiting “nesting” behaviors and their personalities may change as well.[1] Nesting behaviors include collecting blankets, towels or other soft materials and arranging them into a comfortable nest to give birth in. The nesting instinct arises from hormonal changes in preparation for birth.

Pregnant dogs may become more reclusive, seeking quiet spaces away from commotion to settle into their nests. They also tend to become more attached to their owners, wanting more affection and attention. Moodiness is common as well, which is another side effect of hormonal fluctuations. A normally social dog may shun strangers and loud pets like cats. Some dogs even take on a mothering instinct with toys, carrying them around gently in their mouths and tending to them as if they were real puppies.[2]

Overall, personality and temperament changes are quite common in pregnant dogs. Patience and understanding from owners can help an expecting mother dog feel secure and cared for during this time of transition.



Preparing for Delivery

Proper preparation before your dog gives birth can help ensure the delivery goes smoothly. One of the most important preparations is setting up a whelping box where the puppies will be born and spend their first few weeks. The whelping box should be in a quiet, calm area of the home and lined with puppy pads, towels, and blankets. It should be large enough for the mother to lie down and stretch out, but with walls high enough that newborn puppies cannot climb out. Some important features include a pig rail or lip around the edge to prevent puppies from getting trapped. The box should also be kept very warm at around 85°F.

In the final weeks of pregnancy, a dog’s nutritional needs increase dramatically as puppies grow rapidly. Feed a high quality puppy food formulated for gestation and lactation. Break meals into smaller, more frequent portions as the whelping date nears. Always provide easy access to fresh water. Consult your veterinarian if you have questions about optimal nutrition. Proper care and nutrition support healthy development of puppies.

Be prepared with supplies like scissors to cut umbilical cords, dental floss to tie them off, towels for drying and warming puppies, a heating pad, and emergency contact numbers for your veterinarian. Monitoring temperature drop and contractions can help determine when active labor will begin. Be ready to comfort and encourage your dog through the whelping process. With proper preparation, you can ensure a safe delivery.


In summary, being able to determine dog pregnancy early and caring properly for your pregnant pooch is very important. Within the first few weeks, there are some key signs to watch out for like morning sickness, behavioral changes, enlarged nipples and abdominal swelling. Between 4-5 weeks, an ultrasound by a vet can usually detect fetal heartbeats and confirm pregnancy. Abdominal palpation exams around 4 weeks can also help determine size of litter. After 28 days, x-rays will show puppy skeletal development. Throughout pregnancy and leading up to delivery, proper nutrition, exercise precautions and whelping preparations will ensure the health of mom and pups. While some signs of pregnancy may be noticeable at home, veterinary exams and care is crucial for monitoring mom’s progress, administering supplements, diagnosing potential issues and assistance with delivery if needed.

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