Introduction
Around 3 weeks into a dog’s pregnancy, the embryos implant into the uterine wall and the dog’s nipples and mammary glands start changing in preparation for nursing the puppies. This is an exciting time during pregnancy as the dog’s body starts going through noticeable changes. While the embryos are still very small at this point, the dog’s mammary glands are enlarging and the nipples are becoming more prominent. It’s important to monitor the dog’s health and provide good nutrition during this period of rapid development and change.
Signs of Pregnancy in Dogs at 3 Weeks
At 3 weeks into the pregnancy, there are a few early signs that indicate a dog is expecting puppies. These include both physical and behavioral changes as the dog’s body starts preparing for the demands of the growing fetuses. According to Purina, a pregnant dog doesn’t typically show physical signs until around day 40 of pregnancy.
However, some subtle changes may be noticeable around 3 weeks. The dog’s appetite often increases slightly during this time as her body requires additional nutrition for the developing puppies. Her nipples may also start to enlarge slightly in preparation for lactating and nursing the puppies after birth.
Behaviorally, the hormonal changes of early pregnancy can cause some dogs to become more affectionate and attention-seeking. They may want more petting, cuddling or time with their owner. Alternatively, some dogs become less interested in physical activity like walks or play at this stage.
Overall the changes at 3 weeks tend to be quite mild. More noticeable symptoms like morning sickness, visible weight gain and enlarging belly arise later, around weeks 4-5. It’s important to keep an eye out for any changes in appetite, energy levels or nipple appearance at this early stage as they can indicate pregnancy. But a veterinary exam is needed to fully confirm the pregnancy.
Dog Nipples Early in Pregnancy
In non-pregnant dogs, nipples are typically small, round, and pinkish in color. The size ranges from about the tip of a pencil eraser to the size of a pea. The nipple sits in the middle of a round area called the areola, which has no hair growth and is the same light pink color as the nipple.
Changes in the nipples are one of the earliest signs of pregnancy in dogs, starting as early as 2-3 weeks after conception. The most noticeable change is enlargement and swelling of the nipples themselves. The nipples grow in size and protrude more. Whereas non-pregnant nipples sit flush with the surrounding skin, pregnant nipples stick out. The areolas also increase in size.
Another distinct change is darkening of the areolas. The light pink tissue around the nipples darkens to a rosy red or purplish-red color. This happens due to increased blood flow to the mammary glands, preparing them for eventual milk production and nursing.
The nipples may also appear slightly moist or sticky during early pregnancy. This colostrum, or pre-milk fluid, may leak out when the nipples are manipulated. The presence of colostrum confirms hormone changes consistent with pregnancy.
These nipple changes arise from hormonal stimulation of the mammary glands. Progesterone, estrogen, prolactin and other hormones initiate changes that will allow the breasts to produce milk. This allows the mother dog’s body to prepare for nursing even though pregnancy is just in the early stages.
Enlarging Nipples
Around 3 weeks after conception, one of the most notable signs of pregnancy in dogs is enlarging nipples. The nipples will start to grow in size and become more prominent on the dog’s belly in preparation for nursing puppies. According to this source, the nipples may look slightly larger, pinker, and deeper in color than normal.
As pregnancy progresses, the nipples will continue growing and swelling in preparation for producing milk. Mammary glands under the nipples will also start enlarging. According to this source, the nipples can double or triple in size during the course of pregnancy. Monitoring nipple changes is one of the most reliable ways to identify pregnancy in dogs at 3 weeks along.
Darkening Areolas
As early as 3 weeks into pregnancy, you may notice your dog’s nipples and areolas (the skin surrounding the nipples) start to darken in color and become more prominent. The areolas will change from pink to a darker rosy or purplish shade. This happens in response to increased blood flow and melanin production in the area to get the nipples ready for nursing puppies. The color change is one of the earliest visible signs that a dog is pregnant. According to sources, the areolas will become noticeably darker between 5-7 weeks into pregnancy.
Here’s an excerpt explaining this early pregnancy change:
“Between 5 and 7 weeks of pregnancy, the dog’s nipples undergo noticeable alterations. They become more prominent and take on a darker hue. These changes prepare the mother dog’s breasts for the production of milk and feeding of puppies.” (https://rexipets.com/blogs/the-latest/normal-dog-nipples-vs-pregnant)
Increased Blood Flow
As pregnancy hormones increase, you may notice your dog’s nipples becoming redder. This reddening is caused by increased blood flow to the mammary glands in preparation for milk production and nursing. At around 3 weeks of pregnancy, the nipples and areolas have a flushed, rosy appearance as blood vessels dilate to supply the growing mammary tissue.
The heightened blood flow delivers nutrients and oxygen to help expand the milk duct system. It also elevates temperature, allowing ideal conditions for milk synthesis. This physiological change happens gradually in the early stages of pregnancy as progesterone levels rise. The redness is perfectly normal and indicates mammary development is on track for nursing puppies. Monitoring nipple color and enlargement can help confirm pregnancy and healthy mammary function in dogs.
Colostrum
Colostrum is the first milk produced by the mother dog shortly before giving birth and immediately afterwards. It is a vitally important substance for newborn puppies as it provides them with antibodies and nutrients to help their immune system develop and fight off infections in those critical early weeks of life. Colostrum is especially abundant in immunoglobulin IgG, which provides passive immunity to puppies until their own immune system matures.1
Around 3 weeks into the pregnancy, the mother dog’s mammary glands will start producing colostrum. It is a clear or milky pre-milk fluid that is thicker and more yellowish than regular milk. The colostrum contains higher levels of fat, protein, vitamins, and antibodies compared to normal milk. Puppies receive the majority of their immune protection in the first 24 hours after birth by ingesting the colostrum, so it’s crucial they nurse from the mother immediately.
To help prepare for producing high quality colostrum and milk, pregnant and nursing dogs require optimal nutrition with increased calories, protein, fat, and nutrients.2 Supplements containing prebiotics and probiotics may also boost immunity levels in the colostrum.3 Dog owners should monitor the mother dog’s mammary glands for engorgement and check that puppies are able to nurse effectively in those important early days.
Preparing for Nursing
A dog’s nipples go through significant changes during pregnancy to prepare for nursing puppies after birth. One of the most noticeable changes is enlargement. According to Rexipets.com, “As early as the second week of pregnancy, you’ll notice your dog’s nipples getting larger and more pink than normal” (https://rexipets.com/blogs/the-latest/normal-dog-nipples-vs-pregnant). By three weeks, the nipples have swollen even more in preparation for producing milk.
In addition to enlarging, the nipples also darken in color around 3 weeks as the areolas expand. The darkening happens because of increased blood flow to the mammary glands that will produce milk (Wamiz.co.uk). This increased vascularization turns the nipples dark pink or even red as they fill with blood and prepare for lactation.
Around the 3 week mark, the mammary glands behind the nipple also begin enlarging and secreting colostrum, which is the pre-milk substance that contains important antibodies for newborn puppies. According to A-Z-Animals.com, “You may notice tiny droplets of fluid forming on the surface of the enlarged nipples which is colostrum” (https://a-z-animals.com/blog/normal-dog-nipple-appearance-vs-pregnant/). This discharge signals the nipples are nearly ready to supply milk to the puppies that will be born in a few more weeks.
Providing Care
It’s important to provide attentive care for a pregnant dog and her nipples as her body goes through many changes. Here are some tips for caring for a pregnant dog’s nipples and breasts:
Gently clean the nipples daily with a warm, damp cloth. This keeps the area clean and removes any dried discharge. Avoid using soap or harsh chemicals which could irritate the sensitive nipples.
Inspect the nipples for any signs of infection like redness, swelling or pus. Contact your veterinarian if you notice anything abnormal.
Trim the hair around the nipples if your dog has long fur. This allows the puppies to easily access the nipples when nursing.
Apply pet-safe moisturizer to the nipples if they appear dry or cracked. Lanolin-based creams work well.
Provide a whelping box or nesting area with soft bedding as your dog nears delivery. This gives her comfort and helps keep the nipples clean.
Feed a high-quality puppy food diet in the last third of pregnancy to support milk production. Follow your vet’s recommendations for optimal nutrition.
Limit tactile stimulation of the nipples, which can induce early labor. Gentle handling is fine for cleaning.
Contact your vet if you notice leaking milk, swelling, or pain indicating mastitis. This requires prompt veterinary treatment.
Closely monitor your dog as her due date approaches. Be prepared to immediately care for the puppies once she goes into labor.
When to See the Vet
While most pregnancies proceed normally, there are some concerning signs to watch for that warrant a visit to the veterinarian. These include:
- Nipple discharge in early pregnancy – This could indicate a false pregnancy or other issues (South Seattle Veterinary Clinic 2022)
- Signs of miscarriage – Bloody discharge, loss of appetite, lethargy, fever (South Seattle Veterinary Clinic 2022)
- Failure of nipples to enlarge – If nipples do not begin enlarging and reddening by 4-5 weeks, it could signal an issue (Wamiz 2022)
- Discoloration or lesion on nipples – Could indicate mastitis or other infection (Wamiz 2022)
- Signs of illness – Loss of appetite, vomiting, diarrhea, fever warrant a vet visit (Rexi Pets 2022)
It’s always better to err on the side of caution if anything seems abnormal with a pregnant dog. The vet can run tests to determine if the dog is in fact pregnant, catch issues early, and provide guidance on proper care.